Here's my contribution. I believe the pictures on these cards are taller top to bottom than their S&S counterparts. If I'm not mistaken, the S&S cards have green backs while these are normal card-stock colored. The back on mine is actually blank. No overprints, so Frank, you can add "blank backs" to your list above.
One thing I'm curious about are the tiny, little lines on the right and left borders of mine. Really does give you the impression that the cards were cut off the S&S game cards.
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