Hello Franek and Leendert:
I thought it a little odd that Brit aircraft might have been operating in a US area of operations, but my father is certain the aircraft was a Spitfire and the pilot a Brit. I will see if I can narrow down the possibilities using Luftwaffe claims of Spitfires. My father and his fellow GI's were just as surprised to find a British aircraft crash-land in their midst; they were used to seeing P-47's providing CAS for them, Mustangs, bombers, and some Luftwaffe aircraft, but never British. I will try to narrow things down and get back to the board in future. Thanks to both of you.