I believe this used Independent Lock Company lock is from a 1940s or early 1950s Chicago Coin game or arcade machine.
The original key is branded "Chicago Coin Mach. Mfg. Co. Chicago, Ill."

Because of the removable spacer the distance from the inside edge of the front to the face of the cam is about 5/8 of one inch.  If the spacer is removed it increases to about 13/16 of one inch.

It works well with the original key that is included.