I just bought a revolver that the seller said was a 586-3 that was mismarked as a 686-3. It is a low sheen blue black color with ser #BBV6xxx. I think it is actually one of the 686Midnight Black guns that were made very briefly but how do I verify that? Also, there are some wear spots in the finish, is there a way to restore the finish? I don't even know how they made that finish except it was some type of chemical process.