Before making any decisions about what to do with the top ... I need a top.
I had the panel in the clamps overnight.
It the needed flattening, first across the grain with the #5, then across the grain with the #7, and finally along the grain with the #7 ... on both sides.
Then I flipped the cabinet upside down onto the panel, and traced round the top ... offset by 1" all the way round. Then added a bit of curve to the sides, using the template from the front, so that it is approximately the same curve.
I decided to forgo the bandsaw, and use my old faithful hand saws for a slower cut, but solid workholding.
finally cleaning up the edges with the spokeshave and planes, and I have a top ready for whatever it is I decide to do with it.