I was able to identify three pins called P1, P2 and P3 that can be tapped to control spindle speed from Mach3 using the MX3660 breakout board.
Basically I need to pull power from pin P3, ground P1 and reference P2. The reference voltage supplied at P2 from the variable range output 0 to 10volts (or max supplied voltage) of the MX3660 is what controls the speed of the spindle. The monster is alive!
To control this spindle to be on or off I need to use a relay. Since the MX3660 has 4 outputs each supplying 24volts at a max of 70ma of power I decided to order this already assembled relay board. Free trial of amazon prime? Yes please. Three dollar next day shipping? Yes please.
more to come later dudes
