OK - XD818 at Marham was used to play the part of the Tu-16 Badger intercepted in that QRA movie. It didn't fly, of course, but a few blokes in old-style LSJs and leather helmets pretended to be Russians flying it and to look out at the F-4 which had intercepted them. Quite a convincing effort!
XD818 didn't rust away - it was moved to the RAF Museum at Hendon and was re-painted in original anti-flash white.