Kelsey Hayes on 71 demon?

The Kelsey Hayes disc setup was common on the 1965-72 A bodies.

Parts to rebuild the calipers are easily obtainable through Napa, and many other of the large auto parts suppliers. New pistons and new seals are available for the calipers. Hoses are available, and are being manufactured in Argentina, often seen on Ebay through US vendors.

If you wish, you can also get the calipers rebuilt --- even with stainless steel piston cylinder liners with a lifetime warranty --- through www.calipersonline.com With a stainless steel rebuild you are done --- likely forever - no rust!

The only caliper part that is somewhat hard to find replacement -- the brake fluid crossover tube.

Also Cardone is selling rebuilt K-H calipers through a number of parts houses.

Did you try Rock Auto?