It could have been a Belgian gun. There were Many small firms making double guns in Belgium. Most were good shotguns, and some were superior.
French guns I've seen were all well made and trim.
I stumbled upon a well used but still rock solid Manufrance 16ga Robust No. 4 for a giveaway price years ago and have dispatched many grouse and quail with it. It was Ms. Scarlet's favorite gun.
Molly-B died far too young. She was just getting used to it.
Cookie and Rocky guard it between seasons.