I have a spectrum progressive display set up in one of the S2000's at work or in my old Wheel of Fortune machine.
I will get the pin outs on the harness for you Monday if you don't find the drawing for it before then.
Offhand, I remember a Netplex data harness with green wires going into the distribution board on the back wall of the topbox and a 2 or 3 pin power connector as well.
I think the power harness part of it was with a red wire and a black wire.
It could of been a black and an orange wire too....it has been a while since I've looked at it.