"How about Israeli Bf-109s (Czech Avia S-199) escorting B-17s against Spitfires."
I don't know. How about it?
As far as I know the Israelis only ever had a handful of B-17s, but I don't know their operational history. What can you share?
The IDAF, or whatever it's called, also operated Spitfires, as did Egypt and Syria, so I'm betting that could make for some interesting IFF issues.