Make a chamber cast of the rifle barrel chamber, picking up a bit of the bore in the process and remove all doubt.
Given the action and style of the piece and lack of proofs I agree with Mike it is pre-1893. 1893 is about 30 years before the advent of the Nazi party and it is more than likely the drilling is older than that. The buttplate numbered to the rest of the piece makes the possibility that it is a Nazi symbol nearly impossible. Just because something is old and unique doesn't make it rare and valuable.
Value is first of all subjective. Secondly it's exceedingly difficult to place a value on something without personal examination. Kind of like "I have a 1965 Corvair, what is it worth"? Thirdly, someone put on that coat of high gloss poly or varnish or whatever it might be which did nothing to add to the value. Many are frightened of Damascus barrels and the rifle cartridge is still unknown so that limits the market even more. Please don't take all that as any kind of an indictment, it is not so intended. Your pictures are great, I should be so capable!!!!! But there are still things a person needs to see and feel.
If you peruse the auction sites and watch at gun shows....and purchase a few over the years.... I believe you would find the range of the value of the drilling to be between around $1500 to maybe $2500 unless something comes to light that would make it rare and valuable. From what I see and the evidently uncommon cartridge I'd love to get my hands on one just to make the rifle shoot and shoot accurately...but I have a fondness for black powder cartridges and am demented that way...lol!
