This is a large nickel plated brass padlock signed "AM Seal Lock Co.,New York Patented 18 Jan'y, 1870." This rare trick padlock has serial number 1381 on the lock and key. The key has a pin on the top used to put into a small hole at the edge of the key cover. Once that flips open, push the pin at left of sliding cover to expose the key hole. Inserting the key and turning opens the lock. This is a very rare trick padlock in working condition!! - eBay (18 Feb 2010)
This padlock had a high bid of $576 (Plus $6.95 Shipping).