Although often obscured by paint, the chassis number stamped on the front dumb iron is one of the easier nurnbers to find. The precise position is indicated here by Tim Houlding.

The big green Bentley stood in the high street. Suddenly a man in tweeds sprinted from the Post Office and sprang nimbly over the side of the car. The engine started with what seemed like a deafening roar. The only other thing I remember was the driver pushing a lever on the outside before speeding off.

The Bentley was known locally as a Birkin team car. I 'was five, and almost ever since, I've wanted to know the veracity of this unlikely tale and what became of that machine. The closest I ever came, was to trace a man who said he had removed the supercharger.

But such chill trails could be a thing of the past. Bentley buff Tim Houlding has established a unique consultancy that provides current owners, prospective purchasers, dealers and those prone to historical licence, with the essential history of every 3,024 vintage Bentley.

He describes his work as 'Bentley archaeology' — a desire to see as many correct bits as possible all together in one car. In Houlding's view a genuine example is better value and more enjoyable for present and future enthusiasts, and, if you look at life that way, a sounder investment.

Although a replica, this is arguably the most authentic representation of a team car instrument panel in existence. Replica builders should accept there is no dinner-plate-size speedometer, but some rather untidy features like a horn push attached to a steering column spoke.

Interestingly, his research is made necessary by the susceptibility of the vintage Bentley to ambivalent pedigree. There are a number of reasons for this: new cars were almost as demanding to drive as they were fast, and accidents necessitating heavy repairs, frequent. For example, Houldmg has on his books a 1930 Speed Six that suffered three major crashes in the first 37,000 miles of its life. As a result, two replacement axles, two new steering arms and a reconditioned set of front road springs were fitted. The only numbered part would have been the axle, but the discrepancy between what's on the car and what's on the build card, is clearly a puzzle for the historian. Unusually, in the case of this Speed Six, the chassis frame was straightened after one altercation, rather than replaced.

Chassis frames were made and repaired by Mechans in Glasgow, but no attempt was made to reunite a reconditioned frame with the car frorn which it came. This procedure was compounded by former chassis numbers being left on when new ones were added. Matters are made even worse because the works -was notoriously lax about listing numbers from changed components, or even updating its records generally. Normally, only SE (Service Engine) numbers are noted for cars that have had transplants, and in these cases the crankcase inscription, was also changed. Things improved in 1926 when Woolf Bamato took control of Bentley Motors. He regularised numbering and did latter-day connoisseurs a favour. From then on front and rear axles, the differential nose-piece and the steering column were all numbered exactly the same as the chassis frame itself.

Houlding has made an indepth study of the team cars. Typical features for the replica builder to note would be the Bentley plug spanner mounted on the cam case and the quick release oil-filler mechanism visible in the foreground.

When looking for a genuine, original Bentley of 1922-25 vintage, a prospective owner should seek a number sequence which, usually has engine and chassis within about 10 numbers of each other and a braked front axle number approximately 300 below that of the chassis. This is because the early brakeless axles on the first 300 or so cars were usually changed for braked versions, the numbering of which started again at 'one'. As mentioned above, the rear axle and differential nose-piece should have the exact chassis number because of ratio specificity, and finally, the steering column number should be no more than two or three higher than the chassis.

Houlding operates from a cottage in rural Worcestershire, the view of the surrounding farmland obscured by columns of motoring magazine back numbers and mega-enlargements of photographs from the five occasions when Bentley won at Le Mans. He is a man possessed by Bentleys. The badge forms his watch face, the winged 'B' emblem is on the coffee mugs and a set of replica tail lamps impede the route to the loo. But the heart of the operation is a filing system forming perhaps the world's most comprehensive record of the vintage Bentley. Each car has its own entry, including copies of the original Bentley Motors build and service sheets, material from subsequent owners and photographs, if available, of the car when new and in later incarnations. Says Houlding: "I can't go quite as far as tracing who canoodled on the back seat of a client's pride and joy in 1924, but should certairtly know that when it was just days old it had a prang with a Manchester tram."

A previously unpublished photograph from Tim Houlding's unique archive of the 1924 Duff/Clement Le Mans-winning 3-litre chassis 582. Houlding's research reunited it with its original engine number 588. The picture is interesting for several other reasons. The copious amounts of mud have been applied with a brush after a dry race. Duff believed the British public would not appreciate the magnitude of the victory seeinq a clean car. The horn ring and aircraft style switches on the left side of the dashboard are racing features, while present-day restorers should note the somewhat rudimentary fitting on an additional nearside spare wheel.

A query about a particular car will usually prompt a response within 10 minutes, if only to say it was scrapped long ago. Compilation of a detailed history on a well known Bentley takes about a week. An in-depth study of a particularly ambiguous example could involve several weeks sleuthing and cost the enquirer between £500 and £1,000 for a bound pedigree document.

Already there have been a number of notable successes. Houlding has been restoring Bentleys since he was 19 — bits of his first 6-year rebuild were found in a Scottish fence. Recently he acquired a crankcase for his own stock of parts. "It had an SE number, but when I got it home I could just see some heavily filed figures — five something eight. I knew straightaway that it was a reconditioned racing crankcase. Telling the vendor I'd taken away something very special, I added that I couldn't keep it. We subsequently subjected the metal to a sophisticated image enhancer which revealed that unless Bentley put an'S' in, the middle of their numbers, which they did not, the figures were 588. That is the number of the 1924 Le Mans-winning engine. The crankcase was then passed to the owner of re-engined chassis 582 to bring off the historical, and I think ethical, coup of helping create what is now the only Le Mans winning Bentley that carries its correct Le Mans-winning engine."

Frank Clement (left) and John Duff with their 3-litre at Le Mans. Their difference in height (about 12") posed a problem with the driving position.

Not all Houlding's activities have such significant historical implications. "Quite frankly, with the average vintage Bentley, numbers are not that important. You have to allow for straightforward replacement, the dismantling of cars, cannibalization and so on. But in my view it is always important to put the record straight, and when it comes to the valuation of cars, of course, proven continuous history is an asset."

Continuous provenance, and thus originality, was the attraction of a 1930 Speed Six for one Australian client. He was distraught when he contacted the widow of a previous listed owner and she, for whatever reason, denied any knowledge of the car. Happiness reigned when Houlding's records turned up a photograph of the car with her late husband.

This victory brochure was published by Bentley Motors after the 1924 win. Bought recently at auction it contains some later scribblings attributed to Wally Hassan, celebrated Bentley racing mechanic and distinguished automobile engineer.

Another problem with a 'Big Six' arose when a past owner's son wanted to know if the car his father had owned was bought new by the Duke of Kent. Houlding verified the story. The bad news was that it was broken up 40 years ago.

Then there was the American restorer, ostracised by his fellow enthusiasts because his 1929 car, bought new by two Oxford undergraduates and used for an attempt on the US coast-to-coast record, was alleged to have had the fabric body re-covered in the wrong material. In desperation the adversaries called in Houlding to pass judgement. Alas, the texture was not quite correct.

This last ruling reflects his pet enthusiasm for competitive Bentleys, the study of which has resulted in a library of 600 slides. Some of the queries are nightmarishly complex with the potential for damaging litigation.

Take the bizarre case of The Birmingham log-book. A particularly exciting 1940s-built special came on the market with a 4½-litre heavy-crank engine, genuine 3-litre Speed Model chassis, and D-type racing gearbox. In 1946 the special builder had come by an old-style buff log book for a totally unrelated Bentley and used the details to give his delectable concoction a vintage identity. He then sold the car.

Things got complicated when, to reap the benefit of the post-war single-rate car tax attracted by fresh registrations, the new owner took the engine number that the special builder had used, which included the latter's initials, and was issued with a 1949 Birmingham mark on that basis. Years later, though, this innovative Bentleyphile had a change of heart and applied to DVLC for the identity from the old buff log book. It was provisionally allocated to him but he failed to have the car inspected by the local licensing office. Truth, as they say, will out, and by now someone had not only discovered a long-chassis 3-litre frame that went with the old buff log book, but had built a Bentley around it and applied to DVLC for their chassis number's original registration, which, because the special's owner had never followed through, was allocated a second time.

A previously unseen picture of the only unaccounted for team car. It is Houlding's ambition to discover the fate of 3-litre chassis 1040, and engine 1069, seen here at the 1925 Le Mans wearing race number nine.

There were now two cars disputing the same identity, and one — the special — sporting a highly non-Bentley chassis number! Enter Houlding, magnifying glass to the fore. He admits the case had him baffled. "There was no doubt the special had been built on a genuine short chassis as there was no trace of 'cut and shut'. However, I could not find a correct number anywhere on it." In this instance a screwdriver would have served better than the lens. A deck board above the front chassis crossmember was eventually lifted and there, at last, was numerical proof positive. From there on it was comparatively easy to match original registrations to chassis.

This unpublished photograph also shows the only unaccounted for team car, seen here at the 1925 Le Mans, wearing race number nine. Frank Clement (left) and John Duff stand next to it and chassis 1138.

A much more straightforward solution, dependant on one of Houlding's most closely guarded secrets, was provided for a client wishing to 'create' a Blower 4½ — always a delicate area because of the astronomical sums they attract. Says Houlding: A lot of genuine parts including an engine had been assembled but the chassis side rails obtained were not numbered and needed authenticating. The only way of telling an original Blower frame is by four small but unique holes. They were there, and my client was able to carry out a totally honest reconstruction."

Replica team cars are sensitive ground for Bentley aficionados and in the interests of future generations Houlding would like to see better research by their creators.

"Regrettably, many are historically unsound," he says. "There's more to it than spraying the thing green. For example, the colour used by Bentley Motors was, in fact, much lighter than what is now termed British Racing Green. And putting a dustbin-lid-sized plate on the back for a racing number and tying it all together with bonnet straps is not sufficient either.

The competition cars had all sorts of subtle modifications to the electrics, the horns, fillers and so on, and these details are frequently ignored."

Ironically, it is with a team Bentley that Houlding's personal archeological ambitions lie. "I should like to trace Duff's 1925 Le Mans entry, a 3-litre with chassis number 1040, engine number 1069, which is the only team car unaccounted for."

Is this the ultimate barn yard find? If you fancy your chance, it was last heard of as a saloon in Bradford in 1932, owned by a family called Keighley and registered MD 7187.