I have a French 12GA SXS with not a whole lot of information on it.
On the barrel flats it has:
ST ETIENNE 18 3 (both)
Just below this on the Left barrel it has an oval stamp with F8C and maybe a small IE with a line under it at the end
The right barrel has the serial number 1800 stamped just after the sling mount.
The rib between the barrels has a G and what looks like a cursive G or j maybe.
The flats have a Crown with 3 prongs and PT below it, RECTIFIE in semi circle with P.D below it, and the number 65
The Foregrip has:
1800 stamped in the metal, and no other markings
The receiver flats have:
Right side it is stamped with the crown PT
Left side has the serial number 1800
Blow that there is a dot and below that just to the left is a post (it looks like an i with an offset dot)

Barrels are 27" and are not very heavy. They are steel and nor Damascus.
There is a sling mount that swivels front to back that is attached to the underside rib about 4.5 inches in front of the foregrip.
Furniture matches
No markings under the butt plate.
Engraving around screws/pins and on top of action release.

Sorry for these poor descriptions, I have no way to insert images.
Any help identifying is appreciated, Thanks!