Fred, my pleasure. I didn't think there would be any interest - posted this mainly to gather my photos/research and document the hat.
There are at least two more of these that have shown up at auction - a well-worn Johnny Mize and another, I forget whose. I would love to get hold of Berra or Bauer's (or Mantle's). DiMaggio wasn't around then as he retired after 1951, but I can't imagine he would have worn one of these willingly.
Here's Mize's Dobbs, from Lelands (creased photo) and Grey Flannel. To give these two AH's credit, neither made up a pseudo-history for it, as was done for the other two hats:
Lelands-"From the estate of the Big Cat. Terrific felt hat once worn by the HOF'er has golden embossing in the leather headband reading, "Johnny Mize, N.Y. Yankees World Champions in Phoenix, Arizona, 1951." Hat has some moderate foxing but still displays very well. An exciting year in Yankee history, as the torch was passed from DiMaggio to Mantle."
Grey Flannel-"Johnny Mize was a ten-time All-Star, a five-time World Series Champion a was elected to the Hall of Fame in 1981. This hat originates from the esta Hall of Famer and NY Yankees great Johnny Mize. Felt “Dobbs Fifth Avenu manufactured cowboy hat with gold colored embossing on the interior “JOHNNY MIZE NY YANKEES WORLD CHAMPIONS in PHOENIX, AZ 1951”. Appropriate foxing, EX overall."