A customer purchases a well used and worn 870 for plinking and home defense. Not a pretty sight, wood is split and scratched, the bluing is about 60%, but mechanically it's fine.
4 days later, and you can't tell it's the same 870. The original finish is blasted off all the metal and it's parkerized. On top of the parkerizing a layer of black teflon/moly is baked on.
The original stock is tossed in favor of a speedfeed, and to luminate the dark hallways at night a Surefire 618FA forearm is installed.