ok had a bit of a dig amonst the GTR harness that I have now and the GTS4 Harness that is half burnt in the engine bay.
looks like cruise control is a function of the engine harness. the GTR harness doesn't have it, the GTS4 one does.
so for me I'm going to split both harnesses and take the cruise wiring out of mine and toss it into the GTR one since it is in MUCH better condition than the one I have.
for those nutty enough to consider this:
on the outside fuse panel is a spare 4 pin plug. that is for the servo. the rest of it is inside on the same harness. the harness that feeds the steering sensor has extra wiring for the buttons and the clock spring behind the wheel has the positions for extra wires (two extra.) there are three more plugs on the inside harness. one for a relay one for the module and one for the switch. so its a wheel swap with buttons,add teh missing bits and that's pretty much it.
now that I know what is involved I'll start SLOWLY sourcing these AFTER I rebuild that engine harness.
if you want detailed images of what I'm babbling about ask me.