ALT restart batteries

[Learjetter]

I've been looking for awhile... I don't think the bird has a battery pack (it's supposed to have something) installed anymore. NA 77 G model. I'll post some photos--maybe you eagle-eyed folks can assist a sweaty seeker?

Symptoms: at low RPM, the batt DIS light occasionally flickers ON (normal)

Ammeter occasionally waves "hello" (normal) with a slow back and forth wave of small amplitude.

At 1000 RPM, system voltage is 26.8 to 25.2 (low and variable--not normal)
--caveat: this is only indicated on a combo voltage meter/USB charger stuffed into the cigar lighter hole--one man show so it's tough to check voltages with meter at alternator with engines running.

Neither ALT out light will illuminate (checked bulbs, light good) with Battery ON and ALT switches ON (engines not running). --not normal.

OVLT light will illuminate when button pressed (normal) but ALT restart button has no effect. (not normal).

REAR alt will carry the whole load, but shut off the rear and FRONT will also drop offline intermittently (not normal).

Bottom line? The system fails the check in the amplified normal procedures section of POH. It's not mentioned in the logs at all. Several entries about regulators, capacitors, alternators...nothing at all about alt restart circuit.

Cure?
1) fly day-VFR only until all indicators and switches work normally.

2) rebuild alt sensing circuit board and replace diodes, and find the dang battery pack & put new batteries in, then retest.

3) scrap it all and put in two new planepower R1224 regulators.

Thoughts?