Pro’s Pizza produced pizza boxes for frozen pizza with baseball cards on the back in the late 60s. The card sets from these issues are hard to find because the boxes ended up in the trash before the 6x7 card was cut out. This is a "proof" for a large-size box, a never seen example of an entire box, back and sides. Featuring Hall of Famer Ron Santo, this 14 ½ x 15 ½ proof is in Excellent condition. A true rarity. Opening Bid $300.