If you follow the trail in links, Joseph Stephens (#29) was around 21 years old when he moved to Paris and built a house. He reportedly opened a short lived Jewelry business, but that leaves a big unexplained gap between his arrival and the dates of c. 1827-32 cited for the mark. There is no mention of him training in anything (silver, watches, jewelry, etc.), so it would seem that perhaps he was just seeking opportunity in trading goods made by others. Did he have financial backing upon his landing in Paris? Who knows...his father did well (in a typical ante-bellum Southern way) but had a number of children to support. Might be the items were retail wares from a period slightly earlier than cited unless someone had found proof of the years that the jewelry store operated. His history in mercantile and later grocery are established, but it is unlikely the marks are from then.
The only Stephens that Thorn had listed in his 1949 book was a singular individual in New York c.1790, so there is no familial trail to follow here. The fact that Joseph Stephens was not even mentioned may suggest that items were not known by the earlier researchers...why? No doubt much of the existing Southern held silver was lost to the Civil War. The items that have surfaced may have been secreted away for generations, or even seized during the occupations during and after the battles. (If this had been post war trade, would pieces not be more known by Thorn and others, and better documented?) My best shot at this would be Coin, retailed at the jewelry store, possibly earlier than thought by a few years, and rather limited in scope. If the actual silversmith can be found, he may be local, but Stephens may have just gone to outside sources like Philly.