Hi Matt,
Loving hearing about your build! I made a GEM a few years ago and used the Sitec Servo Controller 2 system for the GoTo system. I found that in many cases the wiring configurations were not standard but used the same RJ45 plugs with different pinouts. Fortunately the wiring info provided by Sitec was very good if not somewhat confusing. Look forward to seeing your next update on the "Gaunt"
Chris