Here is a quick page of various resources for the Polymoog. It will be updated as I get more. I know some of these are getting harder to find as time goes on (or, simply scattered in many random corners of the internet).
Shoutout to MartyMoog and Jareth (Synthpro) for helping me on Polymoog issues over the years.
The traditional DIP packages for LM301 are no longer manufactured (much like the 5823 divider chips), so a modern SMD to DIP translation package is needed:
The Polymoog uses twenty four 5823 divider ICs, sometimes (usually!) these can fail over time. Best replacements are available from FlatKeys, you can of course make your own but these are incredibly convenient in a pinch:
Someone once told me they didn't like the Polymoog because it was based on divide-down technology the same as organs, and dismissed it as "not a real synthesizer". Kind of a strange position as sonically the Polymoog is capable of a lot of very nice strings and pads.
It should actually be acknowledged that the Polymoog is not quite the same as divide-down organs that came before it. Through the usage of the poly cards each key actually gets its own unique waveshaping which is not something traditional divide-down snythesizers do. On top of that it still has a Moog filter and unlike polyphonic synthesizers that came after it, the Polymoog has a 71-note polyphony (or paraphony if you want to include the function of the monophonic filter).
Having a monophonic filter on a polyphonic output can lead to interesting effects you can't get otherwise though so there's still a merit to have that configuration. Of course anyone who refuses to see the intracacies in theses details will forever be stuck without creative patch programming.