You can call some of these contacts.
This first one is a heat treating outfit speciallizing in color casehardening only. He will not do the prep work.
Color Case CO Inc 14435 Unity Road
New Springfield, OH 44443-9737
(330) 542-2062
Doug Turnbull Restorations is a full service, high end restoration gunsmith house. They will also do color casehardening on your prepared item or they can do it as well. They would be toward the upper end of costs on such services. For the cost of their full restoration service of both wood and metal, you could buy the world's best Trojan.
http://www.turnbullmfg.com/store.asp...67&catid=19872
Here's some more for your search and information gathering
http://bacheldermastergunmakers.com/...s/Welcome.html
http://www.classicgunsinc.com/
Gunter Pfrommer
Rocky Mount, VA
(540) 484-5555
Damascus refinising
Dale Edmonds Kansas City, MO 816-444-2040
Keith Kearcher Bend, OR 541-617-9299 Restoration and gunsmithing as well.
Dewey Vicknair
Ephrata, Pennsylvania
717-733-2145
Steve Bertram
Boulder CO
303-938-1996 General gunsmithing and restoration