Thanks for the feedback!
I, too, usually make my own gaskets. I've never used a genuine gasket hole punch, but typically I use a hand-held single hole punch (as used in an office setting) to 'nibble' out a circular hole. Good enough for bolt holes and oil passages, anyway.
I also use the ball peen hammer to 'mark' the edge of the gasket. Then, I use either a very good pair of scissors (I have a very fine, heavy steel set that was given to me, years ago) or a set of aviation tin snips.
This gasket was / is for my brother who is doing a cylinder hone & re-ring on his. He, too, was intending to make the gasket himself, but seemed to think it was some special very thin, semi-brittle material and not just 'ordinary' gasket material. I told him that 'very thin, semi-brittle' is just another way of saying 'old clamped-together-for-37-years'.
We've tried a couple on-line places and each has come up "discontinued - no longer available". Looks like he may be going the home-made route, yet...
Kirk