I started a thread several years ago entitled: Russian over flights by RAF crews during the "Cold War" with the help of Tartanterror, Heimdall & several others, covering the North American RB-45's flown by RAF crews in Operation Ju Jitsu. The modified Canberra that flew to Kapustin Yar in Operation Robin & the 15 RAF pilots that converted to & flew missions for the CIA in the Lockheed U-2.
If you have got a few days spare, there was a lot of information that came out.