It's getting harder to find Mantle-signed balls that haven't been on the market before. That's not the case with this unique gem inked by the Mick after one of his multitude of World Series games in the '50s. Though the exact game isn't clear, its documentation is provided by former pro basketball player Harry "Moose" Miller, a center with the old BAA's Toronto Huskies in 1946-47, who was friends with many ballplayers and had access to the Yankee Stadium locker room, where Mantle wrote on a side panel "To Harry, Best Wishes, Mickey Mantle" in blue ink, grading a good 7/10. ONL (Giles) ball is pleasantly toned with a few dark spots unaffecting the valuable signature.