It's John Mew's first special, powered by a flathead Ford V8 from a WW2 tank. It was built circa 1950.
I know this because it was going to be in my next set of puzzles the same week that you used it!
(John Mew was well-known in UK national racing in the 1960s, and for several years he dressed as Santa Claus at the annual BRSCC Boxing Day race meeting at Brands Hatch, usually driving round the circuit in his FJ Lotus 20 with a long white beard and a red costume.)