The advertisement photo I posted gives a pretty good description of this set, but I have many questions:
1.) What exactly is it? Who issued it? How was it distributed?
2.) What year did it come out? The ad is from 1970, but I'm guessing the set came out in 1969 since Bench and Koosman are in it. Or, maybe some of these "cards" were issued progressively between 1968 and 1970.
3.) Is the checklist of 47 players complete?
4.) Is the set worthy of inclusion in TCDB? I assume they're made of heavy cardboard stock, like a 1970 Super (or heavier). The size (11.5 x 16) obviously makes them a challenge for inclusion in binder.
I looked up a few of the players on the checklist in EBay, but it was futile since I don't have a product name to narrow my search.