“U.S. INT REV”. 3 7/8″ high x 2 1/2″ wide. Brass body. Brass shackle. A paper seal padlock. “T. SLAIGHT PATENT NOV.23.69 NEWARK N.J. U.S. INT REV” is stamped on the obverse of the body. “PATENT AUG.5’73” is stamped on the seal. “SLAYMAKER LANC, PA.” is stamped on the reverse of the shackle. Interestingly the original key is marked Eagle Lock Co. We need to investigate this further.