Here is the best photo I could get of the markings on the action flats. I don't see anything that looks like a Francotte trademark on here (or the barrel flats shown earlier). The other markings are the serial # and VERY faint/unreadable numbers inside the horseshoe/large 'C'.
These are all of the markings.
I believe I'm left with the identity as a 'Guild gun', possibly made around the turn of the century and rebarreled in the 1940's.
That leaves my final advertisement to read:
"Belgian SxS 20 ga boxlock, probable Guild gun, good wood,50%+ engraving coverage. Overall 80%+
Blued action; 27 1/2" barrels, current choking reportedly ic/m, barrels moderately pitted, but pattern well; single trigger; half pistol grip stock, 15 1/4" LOP, 2 3/4" drop, factory-added stock extension and hard rubber pad; splinter forearm with gold inlayed initials 'DL' or 'LD'."
Price will be determined soon and the gun posted on the classifieds page.
Thanks to everyone who helped with this detective story. I've learned a great deal and had some fun, too. IMHO, this is another example of what a great place this forum is!