On youtube I've seen some people who had their own tapes from 1978. What's the oldest tape you have? I only make it to the mid '90s myself.
On a related note, if you ever find a really old tape of the BBC's "I Claudius", check out episode 9. It seems there was an extra scene there (a shot of a massacred woman) that is now no longer on the master tape.
I have the full Live Aid also Top of the Pops 1980s