This is one of four cars built for the 1950 racing season by HWM - Hersham & Walton Motors of Walton-on-Thames. They were built as offset single-seater Formula 2 open-wheelers, using 2-litre Alta engines, the idea being that cycle wings and lamps could be added to convert them easily to sports-racing cars.
Three cars were used by the works, raced around Europe during 1950 by drivers such as the young Stirling Moss, Johnny Claes, Lance Macklin and George Abecassis, and one was sold to a private customer. At the end of that year the three works cars were sold off, to be replaced in the HWM team by conventional single-seaters. Two were converted to sports-racers with cycle wings: one later got a Jaguar engine to become the first HWM-Jaguar, and the other went to America to be fitted with a Chevy small-block V8 and was christened the Stovebolt Special.
The car pictured got the more elaborate full-width wings seen in the picture, and was sold to HWM privateer Tom Meyer. It was later raced by the Hon Patrick Lindsay before going downhill, being rescued and rebuilt in the 1980s by Rod Leach with cycle wings.
All three works cars still exist and reside in the UK: this one with a private owner in Worcestershire, the Jaguar-powered one also in Worcestershire with Terry Grainger, who has owned it for over 40 years, and the Stovebolt Special in my garage.