So, not Plomb, but Plomb Empire, and economy line (to Proto) at that, but this is a neat find in my book if only because in nearly ten years of tool collecting, I have never seen another Challenger DOE engineers wrench. Are they left coast common and right coast rare? Or rare everywhere? We've seen a number of fantastic Challenger socket sets pop up here, from the original line in 1939/1940 (Carla, d42jeep), to possibly late 40's/early 1950's (Oldtuleguy) to 60's/70's (mine, among others), but I don't recall seeing any Challenger DOE engineers wrenches. I'll be honest and say I didn't even know they made them like this. The DOE engineers wrenches in my PENENS Master Set are made by J.P. Danielson in the old Controlled Steel panel style. If anyone has any, please post them. I am curious about styles and model numbers. I kind of like the Challenger helmet symbol.
This example is marked 11/16 MFD. 5722 challenger ALLOY USA. 19/32 with a little solid triangle forged into the flip side. Anyone know anything about that triangle marking? ([edit]It's not the Bonney-Herbrand-Utica Triangle mark, which wouldn't make sense anyway.[/edit])