I'm considering having L&M, ATEI or Jagerwerks mill a G19.5 for an RMR. I would like to keep the appearance and durability of the slide as close to the factory nDLC finish as possible while protecting the milled surface. L&M will cerakote the milled surface only while ATEI and Jagerwerks will use black nitride on the entire slide. Which would you choose? Anyone know if ATEI or Jagerwerks will nitride only the milled surface?