I cannot think of a way to make this work. It might work in the middle of a zone, but anything on the edge of zone would be subject to having aircraft flown in from zones that aren't ENY impacted.
Unless you go so drastic as to have that P-51D <poof> into a P-51B or P-40, the Spitfire XVI <poof> into a Spitfire IX or I, Bf110G-2 <poof> into a Bf110C-4b upon entering the zone, and I don't think anybody wants that.