The CAA Library at Aviation House, Gatwick certainly had snapshots (I think it was one edition every two years) starting back in the 1950s of the first OAG guides including the larger telephone-directory style Red and Blue books through the 70s and 80s. The library used to be freely open to the general public and you could just take them off the shelves and take them to a library desk to read at leisure. The library was then part of the re-hack of the downstairs area of Aviation House some years later and I don't know if it is still there, but I'd have to believe that the CAA haven't binned all of this stuff. At least, I hope not. May be worthwhile calling via the switchboard to be put through to the Library and see what happens!