Randall,
I really have no idea of the circumstance under which guns were made at the Francotte factory after they ceased to be imported by A&F in 1966. I did send Pete the names of some of the former Francotte employees in hope that he will be able to raise them since I have had no luck.
Regarding Francotte markings, there were two Francotte shotguns that went to auction at Bonham's in London in July 2010. One gun, number 90610 was marked on the top of the barrels (right tube) "Auguste Francotte" and (left tube) Brevete - Liege". The other, number 91647 was marked only on one tube "Auguste Francotte a' Liege". No indication of what whether the Francotte maker's mark was on the barrel flats. Actually, I just remebered that we have a recently built Francotte in the store now. It's a rifle / shotgun two barrel set, serial number 91713. I'll check it on Monday for the proof marks and date of manufacture.