just rediscovered them ; buried in one of my "oddball" boxes for 10-12 years
I put a modern 60's card in the scan to show their dimensions....the cards are a hair shorter and 1/8 th inch narrower... thinnish photographic stock paper --very very faint pale blue printing on the bright white reverse reads " THIS PAPER MANUFACTURED BY KODAK " but you really have to tilt and stare and squint to even know it's there..
...that's everything I can tell you... I recognize Sal Maglie in a Giants uniform so that puts that particular one at about 1955... Schoendienst looks youngish ...the guy in profile looks like Mantle at first glance but it's not..
...any ideas ? I have 17 of them...others that I recognize are Bobby Thomson and Early Wynn , Johnny Mize , Preacher Roe and Al Rosen...
Thanks , MikeGarcia