On Facebook, Graham Little started a discussion with the following statement:
My definition of an "original" Bugatti.
A car which retains all its major components including:
1) Chassis plates mounted correctly by original pins or rivets.
2) Original major castings and pressing correctly stamped at the factory.
Note - wearing components such as tyres, brake shoes, pistons etc. should be of the same type and quality as original items.
3) Correct "matching" stamped numbers on engine, chassis frame and other major components.
4) A car with original coachwork as fitted by by the factory.
5) Cars supplied as "rolling chassis" and still carrying the coachwork originally fitted.

Patrick Jean-Philippe reacted with an elaborate division in many categories:

Dennis Jenkinson put out his interpretation on genuine, replica etc cars within his book, “Directory of Historic Racing Cars – The Survivors-Genuine, Authentic & Facsimile, Jenkinson in his own words, an attempt has been made to sort out the real from the unreal in order to try to retain a sense of proportion”. Dennis complied a Glossary of Terms to try and label historic and non historic cars as follows:

‘Original’ Almost impossible to find anything in this category. It would have had to have been put in store the moment it was completed. Possibly the Trossi-Monaco special in the Biscaretti Museum comes close to an original racing car as it is possible to get.
The ‘old-car industry’ frequently uses degrees of originality, such as ‘nearly original’, almost original’, even ‘completely original’ but all such descriptions are meaningless as they cannot be quantified. A racing car that has only had a few sets of tyres and a change of sparking plugs since it was completed is no longer “original”. Many components have remained ‘original’ such as gearboxes, cylinder heads, axles, and so on, and reproduction parts are made to ‘original drawings’ and ‘original material specification’, but this does not make them ‘original’ parts, nor does a complete car built from such components qualify as ‘original’, regardless of what the constructor or owner might think. Such a car is nothing more than a ‘reproduction’ or ‘facsimile’.

‘Genuine’ This is a much more practical description for an old or historic car and can be applied to most racing cars that have had active and continuous lives, with no occasions when they have ‘disappeared into limbo’ or changed there character in any way. Most E.R.A,s come into this category as they have been raced continuously, which has meant the replacing of numerous components as they wore out, but the car itself has never been lost from view, nor has its basic character and purpose been altered over the years. Even such a well-known E.R.A as ‘Romulus’ is not ‘original’, as it has been repainted, re-upholstered, new tyres have been fitted and new components have been used to rebuild the engine; but it is unquestionably ‘Genuine’.

‘Authentic’ This term is used to describe a racing car that has led a chequered career through no fault of its own, but has never disappeared from view. The ‘Entity’, which is best described as the sum of the parts, has always been around in some form or another, but has now been put back to the specification that it was in, either when it was first built, or some subsequent known point in its history. An example would be an old Grand Prix car that was converted into a road going sports car when its useful racing life was over, over the years having the racing engine replaced by a touring engine, and eventually being allowed to deteriorate. It is then rescued and rebuilt as the Grand Prix car, with its racing engine replaced, but with new radiator, fuel tank and oil tank, new wheels made, new body-work, instrument panel, seat, upholstery and so on, all of which were missing. The “Entity” that started life as the Grand Prix car never actually disappeared, so the end result of all the labours can justifiably be described a ‘Authentic”. There is no question of it being ‘Original’ and to describe it as ‘Genuine’ would be unfair to its sister cars that remained Grand prix cars all there lives, even though such things as radiator, fuel tank, seat and so on had to be replaced due to the ravages of time and use.

‘Resurrection’ Some racing cars when they reached the end of their useful racing life, were abandoned and gradually dismantled as useful bits were taken off to use on other cars. Eventually insufficient of the car remained to form an acceptable entity, even though most of the components were still scattered about. There have been numerous cases were such components that still existed were gathered up to form the basis of a new car; a new chassis frame and a new body were required and, from the bare bones or the ashes of the original, another one appears. It cannot claim to be the original car, and certainly not a genuine car, nor an authentic car. At best it is a ‘Resurrection’ from the dead, or from the graveyard.

‘Re construction’ This can stem from a single original component, or a collection of components from a variety of cars, but usually there is very little left of the original racing car, except its history and its character. From these small particles a complete new car is built, its only connection to the original car being a few components and the last-known pile of rust left over when decomposition set in.

‘Facsimile’ Purely and simply a racing car that now exists when there never was an original. If a factory built four examples of a particular Grand Prix model, for instance, and there are now five in existence, then the fifth can only be a facsimile, fake, clone, copy or reproduction. If the fifth car was built by the same people or factory who built the four original cars, then at best it could be a “replica” of the four genuine cars, but such a situation is very unlikely. There are many reasons for building a facsimile, from sheer enthusiasm for a particular model to simple avarice, and it is remarkable how many facsimiles have been given a small piece of genuine history in order to try to authenticate the fake, and thus raise its value.

Facsimiles have been built of just about everything from Austin to Wolseley, some being so well made that it is difficult to tell them from originals. Some owners have been known to remain strangely silent about the origins of their cars when they have been mistaken for the real thing. Other facimiles have been declared openly and honestly by the constructors, such as the facsimile that has been built of an A/B-type E.R.A., or the series of facsimiles of 250F Maseratis that have been built. The trouble usually starts when the cars are sold to less scrupulous owners, who first convince themselves they have bought a genuine car, and then try to convince the rest of the sporting world. The disease is very prevalent in the world of museums, on the assumption that the paying public are gullible.

‘Special’ This name applies to one-off cars that are the product of the fertile brain of the constructor. It is probably true to say that no special has ever been finished! It may be finished sufficiently to allow it to race, but inevitably the constructor will be planning further modifications while he is racing it. If the special builder ever says his car is finished, it will usually indicate that it is now obsolete and he is starting on a new one. The rebuilding or restoring of a special to use as an Historic racing car, by someone who is not the original constructor, can mean that the car is rebuilt to a known point in time that appeals to the new owner, or he can continue the process of development where the originator left off. The nice thing about specials is that they are a law unto themselves and do not need to be put into any sort of category. A special can be totally accepted as ‘Genuine, authentic, reconstructed or a facsimile’.

‘Duplication’ This is a disease which started many years ago within the ranks of the lovers of Bugatti cars. Unscrupulous people dismantled a Grand Prix Bugatti into its component parts and with the right hand sold an incomplete car as a ‘basket case’ and with the left hand sold an incomplete car as a ‘box of bits’ The two buyers eventually found suitable second hand components to replace the missing parts, or had new bits made, and we ended up with two Grand prix Bugattis were there had only been one. Naturally each owner claims “authenticity” for his complete car. The Bugatti Owners Club- and the majority of it’s members-strongly disapprove of this practise. Unfortunately the disease has spread too many other makes, especially those that were built in large numbers. At best this whole business borders on fraud.

‘Destroyed’ A simple enough word that applies to a racing car that has been involved in an accident or fire in which no tangible components are left in recognizable shape or form.

‘Scrapped’ This usually applies to a car that is taken out of service by a factory team and either deliberately destroyed so that nothing is left, or useful components are removed and put into store and the rest is thrown on the scrap heap for crushing or melting down. There have been cases of a chassis frame being rescued from the scrap heap and used to recreate a new car. In no way can the new car be describe as genuine. If the factory scrapped a car and removed the number from its records, then that car has gone forever, and a nebulous collection of old and new components can hardly justify the claiming of the scrapped numbers.

‘Broken up’ Similarly if a factory records that a car has been broken up, It should mean exactly that. It has gone for good.

‘Converted’ There have been examples of a type A model being converted by the factory into a type B and then into a type C. The particular car as an entity never disappeared, though it might be difficult to recognise that the type C was once a type A. It is virtually impossible to re-convert such a car back to a type A, no matter how desirable it may be. The perfect example is the E.R.A. that started life as R4B in 1936, was converted to R4C in 1937, and then into R4D in 1938 and was much modified again in 1948. The car still exists as R4D, with a well documented continuous history, and is as genuine as they come, but it can never revert back to R4B.

Personally, I think that every classic car has it's history, and if it is genuine or a reconstruction I do not care. As long as the owner (or seller) is honest about what the car is!