I have a question about my "close to factory original" Underwood (W), 24725XX, M1 Carbine. I try to figure out who made the last parts I could not identify until know. The parts are a firing pin, marking DU and an extractor marking KU. Help is welcome.
Wouldn't DU be Dayton Racquet for Underwood and KU be Keeler Brass for Underwood per Chief of Ordinance memos dated Sept 4 & 5, 1944? I know your Underwood preceeds this memo but the subcontractor's codes would have already been previously established.
While these are possibilities they are not 100% as being correct. The funny thing with sub contractor markings is what can be right for one thing like magazines, the same letters on something else are for a different company. PI on a piston is for Perry Fay Co. and PI on a slide is Packard Mfg. Co. both for Inland.