I was asking because in a catalog from time before Great War there are two o/u shoguns, one sidelock and one boxlock. It’s stated that (one or both of them) was created 1905. A similar sl gun is showed in a A. J. Defourny catalog from the 30s. Here is a link to what it looks like
http://gun-vault.com/defourny.htmPerhaps it was this creation that got other manufactures (before Great War) to develop and manufacture o/u shotguns? Perhaps it was somebody else creation? If so, who’s?
I guess that the connection might be that Brancquaert bought parts from Defourny (and possible from others) who they made up guns from.