Manufactured in 1943 with "U.S.-TEC-CL-72" added to the butt. The included factory letter confirms the current configuration (grips not listed), as well as shipment to Clinton Engineer Works (CEW), Tennessee Eastman Corp in Elza, Tennessee on 27 August 1943 in a shipment of 300 guns. The Clinton Engineer Works was a pivotal Manhattan Project production site which produced the enriched uranium used in the Little Boy atomic bomb which was dropped on Hiroshima, Japan in 1945.