OK, so some progress.

Completed:-

Converted most of the power system to single phase. Need to still sort out the coolant pump however.
Removed the old PC to make space for the CS Labs controller.
Looked at a lot of the wiring, for a long time.
Worked out that from the 3 Axis connectors that used to go to the old PC, I can basically input and output to that 15 Way D sub connector to get encoder signals out and speed reference in as well as satisfying some of the logic requirements.
Worked out where the Spindle Drive 0-10V can be connected to on the standard block. Some of the logic that enables the drive I am not sure about yet.

Fairly happy with the progress although so much to look at and find on other sheets / cross reference, takes ages.

All going to plan, I should be able to move all drives and start the spindle tomorrow unless there is a unit faulty or something goes wrong (hope not).

Will use a laptop at first to setup the CS Labs unit and get going until I can build a PC into the cabinet. Not sure about space as the CSLabs unit takes a fair whack of space, might make another plan.