Anyway, in regards to polishing pads, we use them extensively where I work, but, we do "flatwork". I'm continuing to experiment with different pad configurations to avoid zoning on spherical surfaces, (this is just for fun though, pyrex is soft enough that when polishing with pitch it goes quickly any way (if you have a good grind). Pads do polish quickly, but I'd say once the major pitting is gone better switch to pitch, or you may find your self with more work due to weird zoning. You need to cut the pad in a pattern that will follow the convex tool surface. I've used pie shaped pieces, cut small squares (like pitch facets) withs small cuts on each edge, havn't tried rings or spiral yet.
Prefered pad for cerox: Rodel HSP, .020 thick, with PSAII backing(pressure sensative adhesive)
After mounting, I get the tool wet, and press with LOTS of weight against the mirror.
As I said, a couple of good hours of hard work with pitch, and your there anyway...but good luck.
Bill Marriott btk@ix.netcom.com