Received a small batch of new LM393N comparators that I swapped for IC 5 & 6, and TADA! All pots working, clean VCF Cutoff sweep, Cutoff is not bothering Resonance, etc...
Of course, I was nearly sure of some improvement of swapping in new chips based on my previous swap of IC5 and IC6 giving me two different machines.
Here is a link for the new Cutoff sweep:
https://soundcloud.com/yashn/cutoff-sweep-normal-with-res
During minimal testing tonight, I think there is still some issue: the MG pots might be interfering with the Arpeggiator speed, which was working perfectly before, so I will look into that.
So Korg Polysix Resurrection done, and 'sans oscillator' although I won't be able to calibrate it closely without one yet.
Next step: calibrating the beast, I am confident the DAC calibration will work now and that I will have no more LED 5 stuck, which will help with the rest of the calibration and functionality.
Once calibrated and tuned (I may have to do the tuning by ear, referencing my Kurz), I may do some of the additional mods listed by Terje and others.
Happy.
Yash