It's not a very popular set it seems. Leaf went head to head with Topps and included a marble in their packs instead of gum. I remember having (or at least seeing) these when I was a young collector but I don't recall the packs or the marble. The checklist doesn't have a ton of stars among the 144 players but you will find Duke Snider among the dozen or so Hall of Famers.
The PSA site has a pretty thorough (and wicked) critique of the set. I think they are a little harsh but they do make some good points along side the insights. I have a handful of the cards including these two and while I like them I can't see myself chasing the rest.