55th Wing Aircraft Films
Flight Characteristics of the P-51B Mustang (ca 1942)
Thorough introduction to the B model, with layman’s technical discussion and great flight demo. 30:13 minutes.
B-50 Superfortress: a Stop-gap Bomber
Background on the development and deployment of the aircraft, not much about recon. Interesting description and film of early refueling concepts. 7:59 minutes.

KC-135 - the Indispensibles
Nothing is available for RC-135s, but this Air Force film is pretty good propaganda! 23.46 minutes.