Master Cylinder Sizes for pedal box

Hi all, I did a bit of digging and couldn't come up with an answer to this so I'll pose the question. Using Standard Escort Mk2 calipers on the front (54mm), and P10035 rear wheel cylinders (3/4" I think) can anyone tell me a starting point for adjustable pedal box master cylinder sizes. I currently have 0.625 master cylinder for the front and 0.75 for the rear. These are not sizes I have come up with, but the cylinder sizes that were on the car when I bought it.