Hmmm... thats quite nice. I am not certain that you need to restore it as it looks pretty pristine to me for it's age. Checkering, case hardening, bluing all look fantastic. I have seen others with almost the same design on the receiver but cannot right now place where I saw them.

Others in less condition have sold for $2500 to $3K but may have had the makers name and were in 16 ga.

Hope that helps.