You need to bring the reverse lockout and reverse switch and speedo wiring from the T56 into the cabin. Bridge the overdrive switch. Use the relay that frees the auto stick from park to operate the reverse lockout on the T56 - foot on brake to put in reverse. Use the switch that triggers when in Park - I bridged it so the ECU thinks car is in park. Car will start whenever you want it to.
I brought the wiring loom from the auto into the cabin for the speed display on the dash. Found it simpler to run a single wire to the rear for the reverse light.