Try this company:
Specializing in antique, vintage, classic, obsolete, unique and hard-to-find brake parts, bonding, riveting, rebuilding, drum and rotor machining, custom made brake hoses
Brake Materials & Parts Inc
800 Sherman Boulevard,
Fort Wayne, IN 46808
260-426-3331
http://www.brakematerialsandparts.com/Is that a two ton truck? I'd go to a place that works on box trucks and semis and see what they can do for you.
Rock Auto has parts for a C30. Maybe some parts are shared? They've got 11" and 12" shoes as well as drums and hardware for dual rear wheel trucks.
