Thanks all for the hints and advice. To update, I called Valley Friction in Fresno and they suggested I contact Valley Friction Materials in North Hollywood (no connection between the two companies despite the similar names.) I took the brake bands to N. Hollywood and just got them back yesterday. They did a beautiful job! The cost was about $153 for all four bands (emergency and service brakes). I don't know if that's good or bad, but if they last another 80 years I guess it's ok. For anyone interested here's how to contact them:
Valley Friction Materials
11817 Sherman Way
North Hollywood, CA 91605
818-765-5174