Sometimes the design of the patchbox, the head of it, can help locate a gun.
Just out of curiosity, would there be a rivet holding the toe plate to the buttplate? Rivet, iron perhaps, not screw. Kind of a late thing, done in NY and Michigan, perhaps other places.
If you happen to have the barrel off you might look underneath for initials or name stamped in, which likely would be the barrel maker.
Nice rifle, regardless. Be kind to it, if you intend any restoration.