So I have been slowly working on this refigure for several months of acopious spare time now. My pitch lap has been on a 3/4" plywood disk, shellacked (so-so sealed). Hot pressing was always a challenge the several times I've re-formed the lap, because of the steep curve of the primary mirror. I can quickly get it pressed to about halfway to the center of the mirror, then it's cooled enough that going any further takes lots of time, weight, and repeated tweaks with a heat gun. And still I never got it pressed quite to the perforation.
Then, even using typical strokes to spherize, I keep getting a TDE and hill around the perforation. Even thinning the pitch to soften it didn't seem to help any.
So now, I ordered some dental stone and poured a new tool that has the primary's shape and perforation. So when I pour and press the new lap, it should have a uniform thickness throughout. And hopefully getting to a perfect sphere will be straightforward!