Regarding Jimmy Stewart,
An aviation magazin in early 90's had a more detailed story about his flight experience. If my poor brain remember it right, PIC in B-24 in combat, SIC B-17 non combat, PIC B-47 in early 50's but never in B-36 (but did of course get some stick time during shooting of SAC). His B-52 flight in Nam was mentioned, it was a one time only as a non duty crewmember!