I bet it’s a proprietary finish meant to be a modern interpretation of the old MT11435 ‘leathery’ texture used on lots of camera parts into the 90’s.
MACtac used to sell an deeply textured, adhesive-backed, roll stock that they called “camera grain”. I looked exactly like what was found on the old Pentax/Nikon/etc. SLR bodies.
This looks like a two-step black-on-black effect you could reproduce with a toothbrush, a piece of window screen, and thinned paint.
