Success this morning.  Voltage sensing cable to regulator had a loose connection at the alternator.   That connection was very difficult to get at ...  So now voltage at regulator is about .3V HIGHER than at the voltmeter on the switchboard.   That’s understandable since the switchboard measures the voltage after loads.   I need to motor for a bit to get to the switchover from bulk to absorption- batteries are at 88% now.  But I’m confident that I’ve solved the problem.  Thanks much everyone for your help!