I would love an opportunity to handle this rifle. Looks like a pretty early example. It seems to have a low cheek piece and perhaps, once had a relief finial at the back of the lock. Just worn highlights of the finial suggest a Rockbridge, VA, type of beaver-tail that is blunt at the back and taller than it is long. Clearly, it had a sliding box with a very low dovetail in the butt piece and a shallow slot for its spring latch, cut through the wood from the butt piece to the small box cavity. The large door and small box are somewhat at cross purposes functionally, but in the early period, many variations are found in the experimentation with rifle boxes. In March 2005 Muzzle Blast (pp. 56-7), I illustrated a wonderful early example with a very large door and smaller cavity. While this example is not as exaggerated as the one under discussion here, it has a full half inch or better unused space on each side of the cavity. The finial of the box on this rifle under discussion appears to be brass (?) and nailed on. The parallel to John Davidson and other makers in Rockbridge Co., VA, who used a spear-head shaped finial, may be valid. The design might well have been used by others in a vague emulation of wooden doors. Does anyone out there know where this rifle is? The possible combination of a wooden box with a brass finial seems to be very important.
PS: I noted someone was making comments about cutting patches at the muzzle in conjunction with grease hole boxes. I do not believe either are 18th-century practices. They seem to have evolved in the South in the post-1800 period.