Nicky:
I'm not very good at quoting on this board and i've been cutting down on it lately, but i read your reply and i was thinking:
I can't quite think of anymore pre-79 carryovers than what you mentioned. The only other ones i can think of is 1341-1348, 1421-1440 and a few 1968 ones (1-8, 16-25, 31-36, 57-67 and 69-89).
But it's pretty hard not to reveal any plot info because you can read about some of these episodes on the Archive as Tim has access to them and has revealed quite alot of interesting details about them. You mean you don't want to know anything specific like the quotes or an episode's version of John Costa's outro music, ect.? I understand that. Having an obsession w/ the show's closing credits, i too would love to be surprised at what variation of the outro music John played at the end. Not sure about the others, though.
Also, correction on 1453-1460; it's actually 1446-1460, but again, i guess i can't explain why.