Kind of a long-shot, but can't hurt to try here. (I should probably pitch this at the Rolex Forum but I'm not a pledge there.)

Looking for the screwdown caseback to a Rolex Oyster Perpetual 116000. Mine has an engraving on it that I don't love, and given the chance to swap it out, I would. (Would probably wait til it's time get the watch serviced and have the watchmaker do it for me.)

Price to be negotiated: I don't have the faintest idea what fair value would be here.