The '60s saw Ernie Banks with a card each year while Ron Santo and Billy Williams were in nine of the ten years. The '70s didn't have a player come close to that. The player with the most '70s cards was Rick Reuschel, who was on seven cards, from 1973 - 1979. Five players (Don Kessinger, Randy Hundley, Bill Bonham, Jose Cardenal, and Rick Monday) had six Cubs cards during the decade.
These are the Cubs I grew up with and the cards that I memorized. You could probably show me just a corner of any one of these and I could tell you who it belonged to. This is also the era of the floating heads team cards. There are seven of them scattered throughout.
I'm going to take a little break from these and get to the '80s, 90s, and 2000s in a few days.