The master cylinder for this project is 23mm and can be ordered from: go to www.automotion.com enter: High Performance Master Cylinder For Porsche, Part Number: P916132
Clint Smith at Rebel S Racing can assist with kits to fit early Boxster Calipers to the early 911.
Calipers were purchased from a dismantler in California. Four calipers cost about $600 USD total. Much cheaper option than 930 brakes or Big Brake kit.