You can look on on the auction sites to get an idea.
These are ones I have used. And browse around here:
Extremely knowledgable, more than me.
If you take it apart look at all the little bits for an R to see if it is all matching(more value). At Surplus Rifle you would be able to find out what and where to look for all the proof marks and how to clean it up. I would keep all the papers and box together, thats called provenance and may add value at some future date, to a collector. $$ ? 650 - 800
Is it whispering to you?
How bad do you want it?
And welcome to the forum