From Wikipedia:
Several actors do appear including Gordon Jackson as the young rear gunner.
https://en.wikipedia.org/wiki/Gordon_Jackson_(actor)
Sergeant Ronald (Ron) Burton played the bomb aimer in the 1941 World War II documentary film "Target for Tonight", serving as part of the real-life crew of the Wellington bomber "F for Freddie".
The navigator was portrayed by the shock-haired Scottish airman Flight Lieutenant J. A. "Bill" Broadley.