I have a similar story to TonyO, started collecting serious in 1972, but had some from earlier years.
I didn't realize that I had no full sets from the early seventies, I had thousands of cards, but I guess a few stragglers.
I've since finished most of them, and gone back to 1953 with my quest for Topps sets.
Complete:
1953
1954
1955
1959
1960
1962
1965
1970
1972
1973
1974
1977
1978
1979
1980
Many of the missing sets above, I need just a handful or less of cards (1957, 1958, 1964,1969, 1971, 1975, 1976)
I'm auditing all of my sets now since I recently bought a couple singles that I already had, and discovered holes in my binder for cards that I thought I owned.
My record keeping has been a little slack over the years I guess
.
I think I need just 258 cards to complete the 1953-1980 Topps run, but that number could go up or down depending on my audit.
It's a lot of high number commons in the 60's
I want to get 9 cards off my list before the end of the year if possible. Something about needing less than 250 seems important (it's not)
I actually collect prewar cards with much greater passion, but I really want to finish the Topps run too!!