I think there is a good chance this is not a Jamestown rifle, although it may have NC influences. We may need to look more broadly to find this gunmaker. I also think we may need to look at some old barrel signatures to get a grasp on what the barrel initials are. I read them as "J T C," but others may read them differently.
One detail that may hold a clue is the cheekpiece star, with four large points, and four very tiny points, with the top and bottom large points being rather "chubby" in appearance. A related star was used in several NC schools such as Salem, Mecklenberg, and Catawba, but those stars, while somewhat similar, are more "kissing cousins" than twins. I don't think that type star was used as a cheekpiece inlay in the Jamestown school. but maybe I've missed a couple guns.
In looking a little broader than just NC, there was a gunmaker in Kentucky, who came from NC as a child, and worked in Breckinridge County, KY, below Louisville and along the Ohio River, who used an identical cheek star and also liked to decorate his rifles with numerous German silver inlays. He was Sanford P. Pool, who was trained by his father, Stephen P. Pool, who learned the trade back in NC. While the barrel initials indicate your rifle was made by a different gunmaker, the slim, racy lines of the butt stock, general stock architecture, and generous use of German silver are very similar to work by Sanford Pool of Breckinridge Co. I checked the county listings for any matching initials among its known gunmakers, and one gunmaker in Breckinridge Co. comes close. He is John J. Compton, born in KY in 1827, working there as a gunsmith in 1850 census. I have not seen a rifle by Compton, but it probably would look somewhat similar to the work of his peer, Sanford Pool, a well-known [perhaps best known] maker in Breckinridge Co. in the 1840s and 1850s. Perhaps Compton is not the right man, but the initials and timeframe are close, and your gun looks like it could be a KY product based on inlays and architecture [slim with strong toe and strong comb].
But the real point here is not to limit yourself with assumptions; look more widely, perhaps with NC ties, and eventually you should find the man. Your gun is simply too good to be the only one out there, and eventually the maker will be found.
Shelby Gallien