haha - I have to say that I don’t have any great tips. Use a filter that distorts a bit, in a “mini moog” kind of way (Voyetra-8 and CAT SRM-2 are two of the very few to use the SSM 2044, which was cheap and great sounding). After the waveforms are mixed they go to a VCA that was close to saturating. I think due to a math error the ADSR (first digital adsr in an analog polysynth?) they might be inverted exponential instead of exponential like they should have been (not sure). Also the relatively low level of linear FM between the two VCOs was uses a lot. It wasn’t TZFM, so it’s only in there in small amounts.
BTW, “back in the day” we repaired all kinds of synthesizers. But whenever a CS-80 came in everyone wanted to play it. That and The Strangler’s Oberhiem 8 voice (before the OB-X series, the one that had 4 SEMs in it.). All the other synths - no one cared.