Up for auction is possibly the only surviving sealer mailer box of 50 proof sets from 1961. This box has the original untouched packing tape the box has not been opened since it left the mint nearly 75 years ago. If this is the sole surviving mailer box I believe it belongs in the Smithsonian. We are offering 10x your money back and laboratory fees, that this is an authentic unopened box. Cameos and deep cameos are ultra rare. If you want one you would need to pay thousands, or find one in an unopened set and have the same odds of finding one that a person who received it in 1961. In this box there are 50 chances.