This may seem a daft question, but for a jeep owner it may also be a vexed one.
At the Hampshire Pageant this year I had my first encounter with "jeep police". The guys in question were less than happy with my description of my jeep as Willys and expressed their view that it was in fact a Hotchkiss M201. Now let's first state that I don't give a crap what anyone else's view of the jeep is, but I would like to set the record straight as I see it.
In finding out about my jeep I used the many clues it has and this excellent website:
http://ourworld.compuserve.com/homepages/Jeep_Man/page5.htm
First clue - ITM Number on the right hand chassis rail
At the end of WW2 some 22,000 jeeps were procured by the French for their newly forming Army. Some were lend lease and some were bought as US Army surplus, many were scrap or close to it. The best of these jeeps went into service with the French Army, others were held in store or used for parts. When a jeep was accepted into the French Army it was given a number by 'Inspection Technique du Material' - the ITM Number. ITM 0017939 was issued in 1950. So my jeep was a wartime surplus 6 Volt MB taken into French service. ITM jeeps retained their original MB or GPW identity if they were in good enough condition. My jeep retined its designation of MB365678 right through to its demobilisation in 1990.
The French set up a facility near Paris to deal with war surplus jeeps - essentially a factory to re-furb old jeeps and make "new" ones from cannibalised ones. This was the ERGM (Etablissement de Réserve Générale du Matériel Automobile) at La Maltournée. Jeeps accepted into ERGM in the years 1946 - 1956 were all of wartime origin.
Willys Overland licensed all jeep parts and designs to Hotchkiss in 1955/56 and the French began to build their own jeep - the Hotchkiss M201. M201's had many analog Willys parts but were new build jeeps. All M201's were given French Army numbers at build. These were stamped on the rear chassis rail, my jeep does not have such a number on it.
Next Clue - MALT Plate, under right rear of chassis
When jeeps (ITM or M201) were due for major refurbishment they were returned to ERGM for the work to be carried out. When a major refurb took place the jeep was assigned a factory line number - MALT number. My jeep has a MALT number corresponding to a refurb in 1967.
During the life of the ERGM many modifications were made to the French Army's jeeps. Some were converted from 6V to 12V and some upgraded to 24V or special duty jeeps. Also during this time Hotchkiss Willys Overland France (HWOF) produced many licensed parts including engines and body tubs which were fitted to French jeeps. But some jeeps remained with their original wartime identity, ITM number and 6V system.
Next Clue - HWOF Engine and Body tub
The HWOF engine carries an ERGM plate date 1/12/1965, I assume that this engine was either fitted into the jeep in 1965 or fitted during the 1967 visit to La Maltournée. The engine itself has a 1958 block date, very much an early post war HWOF block. Perhaps the MB engine had given up the ghost by the time the jeep reached its 1967 refit - maybe it had long gone by then.
The body tub is also an early build by Hotchkiss Willys Overland France (Number 9847).
So, this jeep was MB365678 and continues to be MB365678 despite the fact it has a replacement body tub and engine. The engine is an exact copy of the L134 Go Devil, the body tub is as close to an MB one as any modern reproduction and was built with the same tooling as a WW2 one.
If your preference is for a matching numbers GPW or MB's then my jeep is not one of those, but it's also (IMHO) not an M201! 