The big news today is I re-connected with Nyle and I now have all the schematics I need. Just to be clear, I can't share these. I'll post photos, sounds, but nothing that can really be used to reverse engineer the modules, I'm sorry. I owe Nyle that respect and courtesy.
So, now on towards the design! There are some subtle differences in the VCO cores and so I'll have to decide which one to implement. I think the latest one will be where I go, especially since it uses a still-in-production JFET as opposed to the 2N5163 in the earlier design.
Looking at the other schematics, the only other part which seems obsolete is the UJT, but I'm satisfied pretty much any UJT will do the trick. So, not only are Nyle's designs very unique, they are still current and I think I can build them all with in production parts and make them essentially identical to the original.
I'm especially excited for some of the utility modules. I was going to settle for some contemporary designs, like for the tuner/headphone amp, but now I can make the original deal.
I think the biggest project in this will be the keyboard. There are three keyboards, the Synthacon, a two voice Synthasystem, and a "multiphonic" keyboard. At the time, I only had the two voice Synthasystem and so will probably do that one. I'll go ahead and build the keyboard electronics absent a keyboard and will decide what to do about the keyboard later. I'll need to find an old Pratt and Reed or some other buss type keyboard.
Later for this though. I can play the thing with any number of voltage sources. As long as I get a CV and gate, I can have fun. I will need to build one module that will convert voltage gates to S-type triggers/gates, but that should be easy.