A highly polished surface free from pits etc will not rust as easily as a rough surface and will not scratch as easily, therefore it is sound to aneal, file and polish a rough gun on that basis.
If the gun is clean, free from rust has gone to white and the engraving is a concern, it can just be wire wheeled with a little chrome polish, if it is just a matter of prepping, but if there is pitting to do a proper job one can pull a smoke of the engraving and recut it after anealing filing and polishing.
Blasting the reciever sounds nice, but does not do much to create an "original" appearance.
The main point is you should have a consistent finish, and if it is a fine gun, the finish should be very good.
