Personally, I would opt for saying it could be a period box. It has been refinished and the interior is recently re-done, but could be a period box or, at least a late 1800s box and maybe not original to the gun?? There is too much honest looking wear under the fresh varnish to be a recent manufacture. I see filled gouges, lots of scratches, wear to the edges of the wood frame and old hinges. The problem is that it could have been a custom box for any number of guns, since the interior is brand new. There is no way a gun would have sat on that felt for 150 years, or even 10 years without leaving oil stains, dirt, or black powder residue, plus there is not any crushing of the felt where the gun would have pressed on the fabric.
I cannot tell for sure if the eagle is inlet or a decal, but it does look like an inletted piece of brass?? If so, it was polished before the new finish was done. If not, could it be gold or gold plate??
Another option is that it is a very old silverware case that was re-purposed as a gun box. I have used them in the past and converted them into gun cases like the one below.