I have talked with Dan about this gun, and offer this information.
It was made by Louis Royet who came from France after the Civil war, and settled in Reading, Pennsylvania. He is well recorded as a gunsmith on 3 different streets in Reading around the latter part of the 19th century, shown in business directories on Court Street in 1890.
He seems to have made only simple, non decorated/engraved shotguns and every one of the three I've seen had Belgium barrels. It appears he assembled the rest of the gun and almost always stamped both the box lock and barrels "L. Royet, Reading, Pa." The name Fisher on Dans' gun is undoubtedly an owner's name.
Royet, along with Nelson Delaney were the last two gunsmiths to work in Reading and a sample of a Royet shotgun is in the BERKS COUNTY LONG RIFLES & GUNMAKERS Exhibit currently running in Reading and is also shown in the book for the show.
Patrick Hornberger, Curator/author