This pic appears in a number of references (Danjou, Jeudy, etc) captioned as the second FT prototype along with Louis Renault.
I would venture to suggest that it isn't LR. There isn't much of a likeness as far as I can see. Copyright prevents me from supplying photographic evidence, but I think the gent is Charles Edmond Serre.
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Judging by the pic on the right, which I presume is Louis Renault as it says, then I agree, it is not him standing next the tank. Ears are said to be unique to each individual, and the ears do not match, particularly as Renault's right ear appears not to stick out as much as the left one, whereas the gent by the tank has ears which stick out more evenly, a higher hairline, perhaps eyebrows further apart? Different men anyway.
Edit: another link with more pics of Serre as a younger man this is more convincing to me, it may well be him but I think a better pic with the Renault mockup is needed.
It's difficult to say one way or the other. While the two pictures don't look like the same man, the difference could be caused by lense distortion, especially to the one standing in front of the tank.
I think the 1910 shot is a contender. Head's a similar shape, eyebrows wide apart. Ears . . . ?
In the 1936 photo there's a hint of Captain Mainwaring, imo, but by the time of his death Rodolphe Ernst-Metzmaier was a ringer for Bernard Manning.
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"Sometimes things that are not true are included in Wikipedia. While at first glance that may appear like a very great problem for Wikipedia, in reality is it not. In fact, it's a good thing." - Wikipedia.