I don't know if you can still get them but years ago I got rebuilt original calipers from stainless steel brake in New York. They stainless steel plated the body, put stainless steel pistons in, stainless steel retainer clips and a stainless steel tube connectiong the two sides. I haven't had to touch them in 30 -35 years accept for flushing and replacing pads. Back then they would either exchange for ones in stock or redo yours. One of the best things I ever did for the GTS Dart.
