[ChiSoxCardboard]

Hey all. I picked up nearly 600 cards from my wife's aunt recently when her husband (my wife's aunt's husband, not my wife's) passed away. Two of the 1959s had blank backs (kind of, not really). Photos attached. On one of them I can pull back the corner on the reverse and it appears the expected back is beneath the blank back. Anyone know what's going on here?

I realize the simplest explanation is likely correct. Someone glued these cards to something, then cut them back out. The only thing giving me pause is that this was an original childhood collection, and these are the only two cards that look this way. I've also never seen anything quite like it. If this was a kid gluing and cutting back in 1959 or the early 1960s, it is some awfully strong glue!

Thoughts?

Brad