How many movies have Bernard Knowles and Peggy Simpson collaborated on?

They have worked on 2 movies together! Their first movie together was The 39 Steps (1935) and was their highest rated movie together. They have not worked together since Young and Innocent (1937).

Crew
Director of Photography
Role
Alice a Bather at Beach (uncredited)
Crew
Director of Photography
Role
The Jordans' Maid