My initial reaction was (before I read the comment) was that these were stamps from a game of some sort,,, but then I saw that last one, with a "provisional" type of overprint for "11". I would imagine that if these were from a game, they would have not needed the stamped "11" in there. But who knows?
Rough perfs, not a word or letter on them... is there gum on the back?
Sorry for the late reply, bookbndrbob and Bcantin. Yes, I did subject them to UV and yes it is older paper. And yes, I would agree that they are from some sort of game. Two of the "stamps" have gum but the number 3 does not.