One other useless fact. All UMC boxes were made by the C.P.B. Company in Bridgeport. I’d guess the P.B. means paper box, no idea what the C. stood for. Maybe Connecticut. In a former life, I visited the Federal, Winchester, and Remington ammunition plants frequently. Inside the main office of the Remington plant in Lonoke AR was a large mural of the UMC plant in Bridgeport, very impressive. One interesting thing about the Lonoke plant was there was some original manufacturing equipment from the UMC plant still being used. Sort of like a visit to the Industrial Revolution era.