[goheels]

As you look through the cropping pictures go back and forth, notice the height of the checklist boxes relative to the card numbers. All part of the cropping differences.

I have never seen a variation in the first series 1972 CL, card #4. I suspect it is because it was part of a 132 card series. The first series did include the 2nd series checklist but the 1st CL was not double printed.

Ditto for the 1973 BB set of 660--five series of 132. The decision by Topps to not double print the first series or show a preview CL of the next series was followed shortly by a shift to a full release of cards vs series by series. Whether or not that started in 1974 or 1973 has been oft debated here.