I cannot answer all your addendum questions, but not having Williams Evans engraved upon the side plates of the action is questionable. Is this a boxlock gun or a side lock gun? The barrels were proofed in the 1904-1925 time frame. However, I can say with nearly complete certainty that they are not WE made dovetail lump barrels because Williams Evans is not not known to have ever made any barrels.
While we are talking about barrels made by Birmingham barrel makers, both chopper lump and dove tail lump were made in Birmingham.
