Great reference at the cited web site (http://site.voila.fr/guideliege/) re: Auguste Francotte marks.

SHOCKER to me: I can't find a single mark on the gun, under strong light and 3x magnification, that looks like any of the marks attributed to that factory!! Our assumption that is is a Francotte was all based on word of mouth, and that may have led us astray. Its starting to look like the gun may have been bought from the Francotte dealership, and modified to fit my father by their workshop, but it is by some other Belgian maker.

That doesn't change the fact that its a very nice shotgun in a desirable gauge and style, but there is no marquee value. While not a catastrophe, it is disappointing.

What now, gentlemen? Can we put a reasonable value on a nice, used, unknown maker Belgian SxS, so that I can report that value back to the family and let them decide what to do next?