I also found this Signal Corps box. This is bona fide WWII.
The "CH" in "CH-263" stands for "chest" in the Signal Corps' phonetic stock system. Originally intended for spare parts and accessories for the SCR-506 command radio set. At some point in time it was re-purposed for "TOOLS", as you can see stenciled all over it, and that's what I plan to use it for.
Harry A. Prock Cabinet Co. was located in Glenside, PA. The Signal Corps, HQ in Philly, had a habit of sourcing everything it could as locally as feasible. Interestingly, the Harry A. Prock plant was so close to the Standard Pressed Steel plant (think "UNBRAKO" and Hallowell tools) in Jenkintown, PA, (the two towns abut each other), that when it closed, in 1955, SPS bought it to expand their facilities.
The rubber gasket is intact, and it closes up as tight as a drum with those spring-fed latches. A little beat up, missing a corner support, with some rusty hardware, but it's a beaut, with an unbreakable handle.

The bumper strip on the back is fiber.
