This Leonard card is about the size of a 1951 Ringside, real photo, clearly vintage. It says "With All Good Wishes Benny Leonard World's Lightweight Champion." I'd guess some kind of promo piece.
This stamp of Kid Lewis is about the size of a 1950 Bowman card, printed on paper with a gummed back. The right and left sides are perforated like a stamp, the top and bottom are machine-cut, which makes it appear that it was part of a strip.