I didn't clean up the surfaces as good as I had thought, I guess. It leaked... I had to take the clutch cover off again today, and REALLY clean them all well, which meant removing a few more items to get to every bit of it.
The new gasket was destroyed in the process, but I had RTV Black gasket maker, and went without. It seemed to have buttoned back up real good this time.
I was reminded of that old Army saying... You never have enough time to do it right the first time, but you always have time to do it a second time!