I believe this is a rifle that has floated around on internet sites for the last 5+ years, but with a different and smaller percusison lock that fit the lock mortise very poorly. The trigger guard has been a replacement ever since I first saw the gun. The gun initially caught my eye due to its fine stocking, with very clean lines.
I have seen two other rifles with similar swivel type lids, neither signed, probably due to their simplicity. Both these guns were also very plain without any decoration. I always thought this type of simple lid was an "after market" addition to the gun. The gun probably started life without any butt cavity, then had a grease hole added by the owner, which didn't require a lid to hold the grease in. Latter when he wanted to start carrying patches in the butt (that could fall out), the grease hole was expanded and this simple type closure added, with a small metal/wire hook on the lower edge of the cavity to stop the lid in the correct closed position.
The butt profile, side plate, current guard, and filing of butt plate extension all look western PA to me, but I have a nagging hunch that they may have been made a little farther south, due to the very simple box lid, the lack of a rear pipe and the shaping around the rear ramrod entry hole. Someday we might get lucky and see a similar rifle with the maker's name or initials on the barrel. Shelby Gallien