Incredibly rare ball was signed on the one day that the Mick appeared at the ballpark in Cuba in 1957. Sweet spot autograph is on a ball stamped with the famed "Club Almendares" name. A side panel has been notated by the man who obtained the signature, "Domingo 6 Enero 1957" (Sunday January 6, 1957). This is the only time that Mantle spent in Cuba, making it an incredible rarity, perhaps even one of a kind. Likely signed for a player on the Almendares team. EX+.