I'll defer on the value to the other folks here who may have a better handle on that.
Got your note that it's 30 caliber, so most likely a 30-06, some of these have a very close chamber so watch for that when loading for it.
Niedner's never seem to make the same front sight twice, they were all one-off, a banded ramp unless it's cut for a 1903 spline.
Now if this were mine I would refinish all the metal without thinning out the Niedner markings and then rust blue all the metal. Next remove the white line grip cap and buttplate and if the wood is not still cut for a Niedner style metal buttplate I would go with a solid pad to get your correct LOP. If your lucky the white line in the grip can be removed and the cap replaced, if not let me know and I'll take a picture of a period Niedner cap. I would then remove the finish (I use a antique wood finish remover) then a lot of red-oil to try to match an original Shelhamer finish. No small job but well worth the effort.
