Fantastic find, Smoke!

That would be fun to fill up! (I'm used to putting 100+ GMTK tools in the hip roof flip tops, which will pull your arm out of its socket testing your old man strength..., but I presume it's probably a much more comfortable tote for even the largest Speedmaster set.) Good luck preserving that label in the clean-up.
I like your allusory thinking here. We
know Plomb was supplying Monkey Ward's with tools for their Speedmaster sets in the 40's. The HR100 first shows up in Plomb Catalog 19-R THIRD PRINTING, which I dated to NET 10/1946 and NLT 3/1948. They were advertised as "red", but the OD examples disprove that being exclusive, and suggests earlier (late wartime) production. It's reasonable to assume if MW was buying tool-sets from Plomb, they were also buying boxes from them.
Not to dispute Don - frankly, I'm not sure I was fully paying attention to his attribution to McAleer before, but I have the OEM of the Plomb 100HR boxes as "Duplex" in my notes. I can't find whether my justification was deduction (we
know Duplex was supplying Plomb with toolboxes as early as 1940's, and we can reasonably infer they may have also supplied the 100HR's) or if we had evidence.
It's plausible Plomb was buying them from McAleer, which got into the GMTK (Ordnance Dept) hip roof flip-top box biz through the Signal Corps. (Its HQ, depot, and procurement and logistics hub, managing thousands of items and a supply training school, was located in Philly during WWII, many of its suppliers were local, and it used the same type box for their largest TL set.) But your box and the Plomb/MW connection makes me wonder about Duplex due to the Plomb/Duplex connection.