Just received Jeff Jaeger's book on John Small, famed Indiana gunmaker, and am struck by the similarity in the patchbox design. Small died in the early 1820s and this gun is later than that. The style of inlays has some similar overtones, the leaf/sword stands out; Small used the sword on his pipe/axe blades as a touch mark. Just some random musings on my part and until the maker is identified we won't know who made it. Not sure that Small had any children who made guns, but the maker of this one may have seen one and was inspired by it, or could have been a relative. If you can, take a look at the book on Small, which is well illustrated, and compare what you see there with your gun.
Dick