So it was not the input shaft seal.
After tightening up the oil pan when I did the clutch, I no longer have a clutch that feels slippery, and no phantom oil drip.
Did some painting on the front, polishing some stuff. Replaced the PCV valve and a few other odds and ends. Cleaning it up pending sale, so the rising sun will go I think, and the hood will be primed to match.. Soon I'll be driving another Datsun. Something much classier, and much older, and Gloria will have the down time she deserves.
Until then, I'm working on a GM 1 wire alternator mounting to the little A-series.