I've often thought that once the B17, P51 and Glenn Miller were in the UK
Herod, don't forget the P-51 was as much British as it was USA. Developed to fill a Brit requirement and paid for with Brit cold hard cash. The name "Mustang" was even a Brit bestowal. Initially the US had very little interest in the aircraft, the two aircraft given to the US languished on the USAAF test flight line.