Status update:
1. I was able to come up with a conversion face plate that will be able to reuse 100% of the stock wiring with absolutely no modifications. This will allow me to swap back to the old controls should I ever decide to do so (probably not). The panel geometry might look "off", but it's because I could only make the wires' path to the connector shorter, and not longer. I coould not create a 100% copy of the stock face plate because I do not yet have the equipment or skills to design PCBs. So when I went with the terminal blocks, they had to be the panel mount kind which takes up extra space.
After lots of frustration getting everything so every stock connector with no wiring modifications would fit I realized I can get a terminal block longer than needed and just insert more of the male ends into the same one. Problem solved.
2. 5V & 10V power for mesa board and spindle, respectively. I was considering Meanwell DIN mount power supplies for each:
- https://www.amazon.com/gp/product/B005T6RBSO/ref=ox_sc_act_title_2?smid=ATVPDKIKX0DER&psc=1
- https://www.amazon.com/gp/product/B00R5CHZAO/ref=ox_sc_act_title_1?smid=A2TKIOR8M5AQ8G&psc=1
I am not sure the best way to do this. I know the mesa board can imitate a potentiometer but I think I only have 18V nearby to play with. Rather be safe than sorry, as they say.
Advice welcome!