Do yourself a favor and spend a little time setting the cylinders up in a drill press vise, with the hone in the chuck. I have honed scarce, expensive wheel cylinders to the point I had to make new pistons to keep the tolerances right between the piston and the cylinder bore. The rubber cups will expand to seal a cylinder that's WAY oversize, as long as the piston is a close fit to the bore.
A ring of rust pits in line with the hole where the brake fluid enters the cylinder doesn't need to be completely honed away- - - -the cups don't ride on that part of the cylinder. Just get the area where the rubber cups ride completely smooth.
Jerry
