You understand this is a personal opinion...
This rifle is a shooter at best. The puffery about the walnut stock is just that. No patchbox, no carving, and little artistic merit without even a signature place this gun very low on my desirability list.
The price as it now stands is probably in the upper range of the gun's worth.
My experience with our antique rifles is that it's usually best to buy as good a gun as possible. I'd far prefer a repairable gun in poor shape with a good patchbox and the usually expected bells and whistles to a plain gun in shooting condition.
The thing is that a plain shooter is not at all uncommon and has nothing to add to its basic utility. A better gun combining art with function is always a better investment, except if all you want to do is shoot an antique rifle.
As to the ID, this is a fairly late gun. Unless signed or unless a signed sibling can be found, this rifle will remain unidentified as to the maker. Not really a demerit as this gun stands on its own and is what it is.