I would have to say it's from the FNL factory..Fabrique Nationale etc ,Big firm,...the folks who built the Browning Superposed o/u gun & a whole bunch of other firearms.
Francotte was another v good Belgian maker,perhaps smaller than FNL?, but made a lot of lovely guns ,rifles etc....but weren't conected.
So you seem to have an nice FNL o/u,can't help with what model etc though.
So its not a guild gun if it has the FNL marks.
nice one...Franc