Here is another Saint-Étienne "Canons Gallia" gun with the rampant lion. I'm wondering if that is the mark for the Gallia barrel maker.
https://thefiringline.com/forums/showthread.php?t=486445Quoted from the line:
On the undersides of the barrel assembly where it meet the receiver it has:
St Etiennes proof mark
Canons Gallia
A rearing lion in front of:
Marque Deposee
Crochets EncastresThere is only one murky photo of the barrel flats - I've tried to blow it up and sharpen it as much as possible - It does appear to have the lion:

Edit: Turns out same post was on DGS:
https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=276179&page=allbetter photo. I'm assuming that the it was identified as Gerest Berthon by the initial GB.

I'd like to confirm that Canons Gallia was indeed a trademark of Berthon Frères. David, could you check your barrel carefully to see if has a Berthon Frères engraving on it. It will be tiny. Here is the engraving on my Gerest Berthon.
