K&D does not offer a rebuild service for the Interceptor Mk1, Mk2 or Mk3 Calipers. Because the braking system is quite crital to the health and well being of drivers, passengers and the general public, we recommend you have a reputable company rebuild your calipers. If you cannot find one, please give us a call. Mk1 dunlop brake calipers are available brand new. We use the 2 1/8 inch on both rears and fronts of those King-pinned Mk1s, so says Doug. Please see our section dedicated to the Mk1 - 'P1'.