Several out there, though I am personally familiar with:
Will Brothers Restoration
Ossineke, MI 49766
(989) 471-1075

Very nice work. Not cheap, but then again, if it were, it probably wouldn't be for beans...........

Obviously, one should check with Jerry Andrews as to who he may recommend, as he is rather known as the Guru of L.C. Smith firearm repair/restoration.
I did see once that he had dropped the name of Black Diamond Gunworks, but I know nothing about them.

Hope it helps.