Off thread slightly, but I can't resist it ......
I picked up a used, very old RAF Form 414 on ebay a little while back. Why would I do that? Because it belonged to a USAF exchange pilot doing the ETPS course in 1964. That on its own is not special, but the fact that said Captain Al Worden went on to be the Command Module Pilot for the Apollo 15 moon mission probably is ..... if that sort of thing interests you, lol!