....ah!...The Munday Special!
Yes. Well done, I thought it was quite difficult.
It was built around 1932 using a 1921 Sunbeam GP chassis, and powered by the highly-tuned Vauxhall 30/98 engine Munday had successfully run at Brooklands and other events. In 1934 it was purchased by Bainton who repainted it and bored the engine by another 200cc.