There is a locomotive boneyard near where I live at the Northwest railway museum there are about 13 rusting steam locomotives all of them will be cosmeticley restored with two returing to operation in the next 4 years they are both 2-6-6-2 mallets
Utah Rails has an extensive list of locomotive dealers and scrappers:
http://utahrails.net/loconotes/dealers.php
It is basically a listing of companies that have been involved in the used locomotive market, either in rebuilding/reselling or scrapping. It is definitely worth checking out.