Dunno about the B-17 but Chris Bevan certainly flew Doug Arnold's Spits on occasion, and once his Lightning at the Biggin Air Fair. I recall hearing that he wasn't too impressed with it's airworthyness! It's now back in the US.
Ray Hanna flew G-FIRE at Biggin Hill in '81 and there is a magnificent pic of him rocking the wings at very low level just after take off - canopy is rolled back IIRC. Think he also flew Stephen Grey's P-51D Moose at the same show.