I thought it might be prudent to test the individual CGS boards before attaching them to the panel and committing to the wiring. Luckily each board (Digital Noise, Pulse Divider and Gated Comparator) is a functional module in it's own right and I was able to power them up individually on the bench.
So, with a bit of creative temporary wiring and armed with my newly built format converter box, I had an interesting couple of days verifying the functions.
Digital Noise and Pulse Divider working perfectly, just need to figure out how to reliably test the Comparator as it's a jumble of analogue and digital logic!
CGS DIY SWAMP testing