04318-60020 booster clutch kit. all the seals etc. specific to pre1990 70 series.
44621‑28120 is for the seal at the front. same seal for the brake canister. valid to 2006
44628-28120 is for the retaining ring. same ring for the brake canister. valid to 2006
44785-14010 is the gasket between the mount and the housing. same for the brake and valid to 2006
31458-60010 for the piston cover boot that goes over the pedal rod. same for the 60s and 70s to pre1990
these pieces are what i have seen worn. thought the list might help someone when repairing the boosters.
or if you are replacing the masters then just order these seals and retainers and replace for preventive proceedure.