Need schematic/repair manual for CRAFTSMAN 82320 DMM

[Chrigel]

The CRAFTSMAN 82320 is a SEARS rebranded DMM with analog indicator that is manufactured by MASTECH as sold as the '9700' - it was really useful until it started "misbehaving":
For a time the DMM part was ok but analog meter rests at 45 uA (=45% FS) for all ranges, then DMM developed a bias of 450mV. The came more erratic behaviors on various ranges, no resistance measurements.
The reference votage of the LM385-1.2V is 450mV - obviously incorrect.
The CA3130 drives a full phase rectifier but it it not directly connected to the analog display.
I don't have a clue how the 100uA analog meter is driven (off the resitance cascade or with a DAC if it has one?)
The actual DMM circuit is under an epoxy blob, (probably a 7106) but I don't know which would be pin 31 to check the analog input (200mV)

Any help including cicuit drawing, calibration procedure, repair manual, youtube video or other miracles would be greatly appreciated.
Best,
Chrigel