Genuine AP Repair kit for
GMC159 front to rear imperial union type master cylinder 1968-75 and
GMC160 diagonal split 1974-7 these dates inc innocenti/canada and other export options.
The cap with seal fitted for this round body type is available as
AAU3815 and not included in these genuine kits, but the cap seal is often found in the spurious non genuine kits advertised.
when bleeding these cylinders after a repair kit has been fitted you will need to bleed both front and rear wheel cylinders at the same time to get a decent pedal so help will be required