This is a vintage brass Corbin surface rim lock. Rim locks are surface-mounted on the inside of a door, rather than installed within the door stile like a mortise lock.
Brand: Corbin, a company known for commercial-grade door hardware since 1839.
Material: solid brass.
Operation: It is typically operated by a knob or lever and may use a skeleton key and/or privacy bolt.
Dating: These types of locks were common in the late 19th and early 20th centuries.