Many thanks 300EE320, your harness replacement DIY report was first class- made life very easy.
I have installed the new harness which took a while to ship. Had tech to reset codes etc and all is fine. Throttle actuator and cruise control all working. I believe like 300EE320 that the wiring on the throttle actuator may be deteriorating as well but my instrument tech believes that is repairable. Time will tell.
Thanks to everyone who contributed to this thread
1993 320E 140,000km