BSA Streamlight bicycle and Winged Wheel engine from 1953. "The Winged Wheel was the only ‘powerwheel’ available to the British market besides the Cyclemaster. So although cycle attachments were now being displaced by mopeds, the Winged Wheel did hang in there for a few years and quite a few were sold..." (from cyclemaster.wordpress.com)
Streamlight bicycles first appeared in 1940 catalogue. They were designed for blackout, so they were all white. In a short time the idea was abandoned; Streamlight brand disappeared from a severely reduced bicycle range the details of which were circulated to dealers from December 1941. BSA had ceased production of their 3 speed hub gear in 1939. Production appears to have started again by 1945. Streamlight brand was continued, too, although with a black finish instead of chromium plating.