The sidecar shared in 2 pieces... a classic joke for this kind of film The bike is an Indian but I am not sure which model. The heavily valanced front guard would suggest post WW2.
Strange modification It's 45cu in Harley-Davidson and also sidecar is prewar Harley model. Most probable is '37- Harley-Davidson WS (factory sidecar model of WL) I guess. (sorry, trailing link, engine mounted position and exhaust port direction doesn't match Indian) Fourth to sixth thumbnail pics are another brit bike, but not sure.
