Getting this 6 inch blued Python from its original owner. Is this "N" an inspector stamp? He bought it in 79 which matches the serial number. Don't believe that this was ever refinished.Just puzzled by the letter. Is this where they stamped the nickel guns? Did the pachmayers not come up as high on the grip frame as the target stocks?This will be my shooter python. Locks up nice and tight. No scratches or any bluing loss. My other two are new in box.