that went well
I've added two pics one is of the switch is yours thee same if so either remove the bolts on the perspex cover , or with the cover open drill a small hole in line with the allen bolt on the switch housing. remove the interlocks one by one and give em a clean, they probably have not been cleaned since the 90's.

Some lathes were fitted with limit/homing switches many more have only the limit switch to stop you from machining the chuck randomly, you mentioned 2 circuits for the switches, one is for the Z limit ,t'udders for the interlocks.

Quick question did you move the feed pot on the control panel as from memory if its at minimum the axis will just sit there
Again let us know how you get on.

The boards fitted to yours, i haven't seen those versions, top board is the same on most with different components for differing spec.

When you've got a minute can you move the top board ( easiest way is to remove the tow stepper connectors, remove the nylon nuts, then move the top board over a bit an take a few pics of the lower board., and one of the optoisolated board on the speed controller.

A quick note about new control boards is if you want to use the control panel your going to need at least 16 - 20 inputs.
tomorrow i will find the stepper driver data sheets and the index/timing pinouts

i will also put up the dimensions for the limit switch actuator

would look now but i aint had no sleep since Monday