I'm sorry to be so ignorant, but what is an "extension rib stop plate" as I can't find this fault. Also I don't see the brazing to the extractors. Still just trying to learn. And what "Grade" is this supposed to be with the barrel engraving? This thing has me totally confused, thank God I'm not buying.

There is no stop plate on that gun. As it is an extractor gun. The actual rib extension is beat up some.
The gun was and still is a DH grade.