I agree fully with Chris on this lock issue. I collect Kentucky's early firearms, but I keep an eye out for all interesting southern guns. As you move south, away from the industrialized northern states, many later guns continued to used flint locks throughout the 1830s and well into the 1840s. In Kentucky, many better gunmakers switched to single lock bolts [similar to percussion guns] on flintlocks in the early 1820s and continued the practice for years. The more rural an area was, generally the longer they continued to use flintlocks. From my experience, when converted flintlocks were mounted on newly made percussion rifles, they were almost always a low-to-mid quality gun, not a high-grade gun. When a fine southern rifle is encountered with a single bolt and a converted flint-to-percussion lock, you can usually find other hints that it was originally flint. Some Appalachian rifles, called mountain rifles in Kentucky, used flint ignition well into the 1850s. The common "reason" tossed around has always been that they didn't need/couldn't afford the added cost of percussion caps, and when they could, caps weren't always available in their back-woods little country stores.
Shelby Gallien