Can an "expert" distinguish between London cut engraving and Birmingham cut engraving of the same pattern? I think definitely not. Can an "expert" make a pretty good guess based on the pattern itself? Yes. Yes because house patterns are fairly well known and because most boxlocks were made in Birmingham (which dramatically eases the question). The question if engraved in London or Birmingham falls into the same category as was the gun made in London or Birmingham. A much better question is, "What was the original quality level of this gun?"

DDA