I have recently been researching Germans and Austrians who served in the RAF during the war, and apparently there was a George W Berger DFC, who was born in Austria. Flew Sunderlands and Mosquitos.
There is a possibility the DFC would be listed under his real name (which I dont have at the moment).
Another interesting pilot was F/Sgt Ken Adam who flew Typhoons in 609 Squadron. He was born Klaus Hugo Adam in Berlin in 1921. Came to Scotland in 1934 and joined the RAF in 1941.