Very nice find you have there. For sure get those white line spacers out of there. After that, it is up to you how far you want to go. I'd say the gun is worth spending the time or money to have it done as best you can if you do decide to restore it. One of the things Niedner's was known for was there rust blue. Whoever does the blueing should get a chance to look at a few original Niedner blue jobs before starting. Every Shelhamer stock I have seen has had a Horn grip cap so I'd say that is likely original. I think Shelhamers inletting on his early stocks was much better than on his later stocks. Yours seems to support this as the inletting on your stock looks to be very well done.
Very nice find, congratulation.
John
