Bought a new(good, checked, used,) OPR and installed it in my 380SE this morning. I removed the ICU also and cleaned it with Contact cleaner and scrubbed the connections that appeared to be corroded(brownish color, not black but not shellac or grease either. Cleaned the connector pins and the connector also).
Re- installed the ICU and installed the new OPR. It started right up went to approx 1200 rpm, then immediately dropped back to about 500 rpm, then started searching with the rpm fluctuating between 500 and 1000 rpm and then settling at 750 rpm. I also un-tanked the old OPR and noticed the same type of corrosion across some of the contact points on the MBoard. Scrubbed the bejeebers out of it too. Have not re -installed that one to see if it is good or not. (this one rattled too, but I think it is the MBoard shield plate(micarta or plastic). Didn't rattle when I was finished and back together. Haven't checked this one out yet but all contacts were solid.

Took the car out and ran on the 14 Freeway and a couple mountain roads back home and NO dying at stops or anywhere. Came back home and she idled at about 600 in park/600 in Drive or Reverse (with my foot on the brake. Idles at about 750rpm at stops.

Now to tackle the CCU and the Heater Fan relay problem.
But the old girl IDLES now.

__________________
1986 Euro 500SEC "RUF" 9:1CR, "Rose"
1985 Euro 500SEC Cabriolet AMG Widebody
1982 Euro 500SEL "Blue"
2001 Texas Heeler (Aussie/Queensland X) "Sulphie",
2012 Queensland Red Heeler "Squeak"
Best dogs I've ever had.