Here is a hobby unicorn: an R340 Sport Kings premium of Dempsey, Baer and Carnera using an image from the MGM film The Prizefighter and the Lady. There are two known specimens of SK premiums, this one and Weissmuller.
https://www.sportscollectorsdaily.co...ings-premiums/
1951 Ringside salesman's sample with Marciano RC:
1949 Sommers & Kaufmann Lefty O'Doul signed card. PSA and SGC pops on this card
unsigned = 0.