Cool topic. Here's a contribution to the pile of "one knowns" being shared here... Of the 19 currently known signed 1952 Topps Mantles, this is the only one with a "playing days" autograph. Signed on Friday March 29, 1968, at Payne Field in Sarasota FL, before a Spring Training game with the White Sox. Though we'll never know what could be lurking in someone's attic or basement out there, it tickles my imagination to consider the possibility that, based on the 19 that have surfaced, this could be the first '52T card that Mick signed
