My turn for help with Pulse multiplier for test rig.

[EddyCurrent]

This does not directly answer Dean's request but . . .
If I was building cnc machines I would have as a minimum a box with a bob, power supply, 2 x stepper drivers, vfd, all wiring to a bank of terminals to allow easy connection of limits etc.
This would be connected to a PC with a parallel port running Mach3, there would be two sockets mounted on the outside of the box so that by using a flying lead, individual stepper motors could be connected or if the machine used two steppers on X this could also be accomodated.
This system would allow use of a remote pendant or you could use the Mach3 interface to directly enter G0 codes for moving the axes around, the bob would allow connection of limits and home switches for test purposes.

I believe this would cover all the requirements specified by Dean in the most productive and hassle free manner and from what I've read he probably has all the required parts already, unless of course he has some other, not yet revealed, idea for using the minimalistic approach.