I believe I even have a Mike Kreevich baseball card with the Sox, early 50s

I think you're mistaken as Keevich played for the Sox from '36 - '41 and was out of baseball by '46.  Topps or Bowman never made a Kreevich card.  When I was searching for a photo of Kreevich to use in the above post, I only found one card and that was a '44 Play Ball card where he was depicted in a St. Louis Browns uniform.  The large photo I ended up using was Kreevich in a Browns uniform.  If you really have a Kreevich card in a White Sox uniform, it's an 'off-brand' rare card.  Probably worth some money.

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There are a couple of postcards/photos that show him in a Sox uniform but they aren't 'trading cards' per se.

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