I would include Niven as well. Left Hollywood in 1939 to serve for the second time in British Army. Landed at D-Day a few days after initial wave, was at the Battle of the Bulge and presented LOM by Eisenhower.
Included in the WW2 bunch is Humphrey Bogart. The classic trademark mouth thing was from a wound received when a zero crashed into the ship he was on. (If memory serves me)