Thanks for your feedback. Don't know if we have made any progress at all, but here's an update:
Discovered some loose battery connections on the chassis batteries yesterday. (They were serviced just a month ago, and have not produced any symptoms in over 1500 miles) So I pulled both chassis batteries and Auto-zone put a full charge on them and confirmed that no cells were deficient. Coach started right up, showing about 11.4 to 11.7vdc on the Silverleaf. This voltage remained fairly steady for the next hour, so it appeared that the alternator was at least not allowing the voltage to decrease, though it was suggested that if we would drive for 30-minutes or so, it would probably reach the desired 13.4vdc. We turned the coach ignition off and started the generator, which ran for a time, but stopped. By then, we attached the tow-car and departed our Autozone parking lot haven. Within a mile, the lights began dimming, and by the time we exited a mile later, the lights were useless for driving (dark by now) and upon pulling into a Target plaza, the transmission refused to shift. We coasted clear of traffic, let the engine run until the voltage registered above 11.4 again, and made it to a safe spot with tow-truck access/egress clearance.
Spent some time in the Prosine 2.0 2000 Watt inverter manual this morning, started the generator (which has now been running consistently for 4 hours+, and set the Prosine for Inverter to AC In, and the Charger to Charging. Initially it was charging at 11.2 V DC - 98 Amps, but at this point has 14 V DC and is now charging at only 38 Amps, which leads me to believe that either or both battery banks are in better shape, but not sure enough to chance another run to find out.
So my questions now:
1) Which battery bank(s) are likely responding to the Prosine?
2) Does it still point to an Alternator issue?
3) Would the auto-electric/alternator rebuild solution be better than a Caterpillar service center for this issue?
Thanks