The only difference that I can see between the power brakes and non-power brakes master cylinders for a 62 is the cut out underneath. Note in one of Paul's photos the "square" underneath the master cylinder, and in one of Junky's photos the "square" has what looks like two sides ground down to produce a space, which I always assumed was for the vacuum hose to slot into. My car was originally non-power braked, but I installed a booster and kept the original screw-top non-power brake master cylinder and it works great. I got my NOS master cylinder from Auto Parts Obsolete for about $45 a few years ago, but the prices appear to have gone up a bit since then...