There was a nice box compartment under the motor control that previously housed the leadscrew bearing, but is now empty, so I decided to use this to wire the inputs back to a terminal block. It will be easy to seal this box to stop coolant causing problems.
At this stage I will be using inputs from Spindle Index, as well as a combined Limit/Homing switches.
The cable back to the control box is shielded and grounded to the lathe frame to hopefully reduce electrical noise and false triggering. This cable is routed under the lathe well away from power cables. Wiring back to a terminal block makes it really easy to setup and test - Img 1.
After testing the limits, I decided to tidy it up by running the wires for the X axis microswitch through a 9mm flexible plastic tube to keep it out of the way. I think it looks great and is very functional - Img 2.
I had 2 inputs left on the Gecko and I wanted to add a couple of switches. It was quite easy to drill a couple of additional holes in the control panel to add e-stop and cycle start switches. These were wired back to the terminal block and work perfectly.
I forgot to take any pictures of wiring up the stepper motors, but this was relatively simple. I used shielded cable and these were soldered to a speaker plug for easy connection to the controller.