Joe, thank you very much for that detailed answer. I know considerably less about 1911's than single-actions. And I only just recently finally got Kunhausen's SAA book. I should get the 1911 book.
As for blackening, that might be hard on an a shiny all black pistol. Silver sharpie maybe? But then, I think you pointed out the culprit as a loose extractor, since it failed that rather simple test. By the way, I've only shot this gun in two small matches, 182 rounds total through it. So I rather doubt that extractor is going to tighten up with break in. The older nickle gun has only 2294 rounds through it, still pretty new. It passed the extractor shake test and was noticeably tighter to the touch.