This tandem brake master cylinder comes as the cylinder only, without the Reservoir. It is the UK later 85-88 style that will fit Australian cars if you want a new one.
The cylinder bore is stepped and has a larger lower flare fitting (12mm head), but this pipe actually goes to the opposite end of the 5 way valve then the Australian master cylinders. This neccestates at least one new pipe that can be made easily.
A kit with ready made pipes to the 5 way valve is also available.
When using this master cylinder you may also need a P9180 tube nut.