thanks to all for the info and tips. I had actually got the cylinder off early in the piece and re-surfaced the top, after doing the same to the head only at first. The head and cylinder surfaces now seem to be spot on when I sit a straight edge on them.
As far as the annealing is concerned, I held the gasket over the gas stovetop burner till it was dull red and then quenched it in the kitchen sink. All done rather quickly while the better half was in the shower of course.
After reading Nathan's comment about the raised ridge in the gasket, I had a better look at it last night, and it has seen better days so a new one has been ordered. Hopefully it'll all hold together this time.