Engravers are artists, with varying degrees of talent. Also, the art can be and is often influenced by the world view, cultural milieu, and other eddies and currents that carry the artist and their clientele. Most of us have seen a similar interpretation of dogs and birds on other guns. I had one from England made in the 1880's with very similar execution of birds and dogs. Monet and the other impressionists are seldom scorned for their skill as painters, yet exquisite works by nonconformists of the day such as Alma Tadema and Bourgereau are sniffed at by collectors and critics.
What I found interesting and unique about Gils's gun when I first saw it was indeed the engraving. Way out of the box for La Manu, and as James pointed out, most likely a customer request. Granted, the execution of the engraving is not in line with typical MF work that I have seen. But it's really unusual, IMO "good enough," with a beautiful stick and according to James (who lives and dies by the barrels), near perfect tubes.
Well done Gil!
Mike