Any name it writing anyplace on the piece? Obviously the lock isn’t original. Is the barrel original to the stock? I can’t see the tang or how the breach end meets the wood. There are lots of experts on the American Longrifle Forum that could identify the “school”. All I can tell so far is it’s a half stock percussion. Do you know the caliber, barrel length, length of pull? All this can help identify it more. If you want I can PM you my email and then you can send me some pics and I’ll show them to an old gun builder/smith at my BP club. Our rendezvous is this next weekend.