I don’t know if he was a marine armorer, but I know that he lived up out of Enterprise Or. Some old shooters around Oregon referred to him as technical rocket scientist/machinest. I never did meet him.
If you were to look closely at that trigger most people can’t even tell how it works let alone how or where to adjust it. It’s got a sear that dog legs inside of it. Work of art. I’d list it up there with that inline striker a trigger built out of FL