While it might be that Verney-Carron made the first truly mass produced OU's in France, the Petriks were made during the between the wars period.

The receiver is interesting. While the exterior looks something like a Merkel, the interior photos verify that it's a totally different bolting system. Nothing like the Kersten.

Gene, my memory isn't 100% on this, but digging way back, I seem to recall that "choke" on a barrel (minus rectifie) indicated full choke.