The rifle appears to have a long, 2-screw tang, despite being hard to see. Longer 2-screw tangs usually indicate a "southern" rifle, as does the pointed ends on the side facings [raised panels] where the lock sits. Walnut stocks were used in most states, but perhaps a little more heavily in southern states, so the gun probably came from below the Ohio River. These later, more generic or less decorated half-stocked rifles are hard to place, since they have limited details to help identify the maker.
Your best chance at identifying and locating the gun is if there is any trace of a name or initials on the top barrel flat several inches behind the rear sight, where the maker would have signed the gun. The barrel may have been shortened a few inches at the breech, but there's still enough barrel left behind the rear sight that, if signed, some trace of name/initials should be there. If not, the gun probably cannot be identified much further than possible southern origin.
It would help to see a good picture of the back side of the butt showing full butt out to about 6" past the rear side facing opposite the lock plate. Then we can see if a cheekpiece is present or absent, and if present its shape which at times helps put a gun into a specific region. Make sure to get the lock bolt washer in the picture of the back side, since its shape may also provide a clue to the gun's origin. And please include a good picture of the tang, to verify its length and number of screws.
Shelby Gallien