....???
Are you looking for somebody to do a restoration?
-OR-
Inquiring about others that re-do, restore, techniques, etc.
I'm thinking most just tackle this job themselves, I know I do.
I like to buy older Lett grips fit them to a specific frame , re paint the medallions, change out the later silver screw/escutcheons to blued when used on a blue gun.
As for refinish, I like to strip them using lacquer thinner generously and then refinish with a darker walnut Watco dainish oil & some minwax black, sanding in the first heavy thick coat, let it sit over night rub it out and then a couple of "wipe" finish coats, then a few weeks of dry time. This method produces a nice oiled look.