Have you ever seen this?
I think this could be the 2 1/2 hp Tankette by Ronald Trist & Co of Watford?
That's it!
You may have seen the picture of the chassis (below) in Georgano (oddly, it's missing a caption in the edition I have), but you may not have seen the whole car before.
Perhaps this wasn't a hard puzzle, but I thought there should be a picture of a whole Tankette available to look at in AutoPuzzles!
As my Dad used to say "They're all easy if you know the answer". Love the grim determination of the occupants. Any vehicle as unpromising as the Tankette rightly deserves celebration!