It works! Seeing just over 14 VDC on the panelboard voltmeter.
Had the alternater rebuilt (bad diode & bad on-board regulator) and the old external regulator was bad too. Dumped that and got things working with the integral regulator.
Next is to learn how it all behaves with our use/duty cycle, characterize my loads & amps, that is the fun part. The no-fun part was changing out the alternator as it mounts beneath the 24VDC alternator. I can do it in harbor, but would not want to swap it in open water. A spare alt coming too. And now I know who to go to for electrical, got cut sheets for alternator, source for spare pulley, understand my shore powered charger better, etc.
Thanks for the ears and advice here. I think I will put the next B.O.A.T. (break out another thousand) towards a 2kw Honda generator. I need to design and fab a secure isolation mounting frame for cabin noise to be tolerable.