The lock is an original lock from National Lock Co in Rockford, IL from the 1950s. The lock is coated with a black finish and was used on some Gerstner Chests. The lock comes with 1 Original National Lock Key and Nickel Split Rivets (we don’t have any more black rivets).
The lock is a direct replacement for National Locks that had a 56-E-xx key number.
See pictures for hole spacing.