Awesome Mark. I think that is first gun I have seen engraved with a Shoveler Duck or is that a Merganser. That is rare.
Second thought that could be a Ruddy duck. Can't make out the tail. It looks like a Brittanies. Just kidding that is neat old engraving.
Ya know gun makers will sometimes name their guns after a game animal and sometimes owners will nickname their guns. You got a candidate.