This item is an RCAF lead seal press, likely 1950s era, used by the RCAF after WWII. A lead seal press or crimper, is used to close and engrave metal bands to provide identification and security against tampering, or to securely join wires to things like turnbuckles, such as with aircraft control wires between a control column and a control, such as an aileron or rudder. Upper and lower dies are interchangeable and can be removed with a set screw. This lead seal press is unique in the stamp it makes when embossing metal metal leads with RCAF indicated the work of Royal Canadian Air Force tools and maintenance.
RCAF Lead Seal Press