Mercedes Benz repair: Mercedes Stalling, crank pulley, number search results

Question
Good morning.

My 1983 380Sl 170K miles, engine rebuilt at 120, stalls frequently but not on a regular basis, perhaps 1 in 10 trips. Previously the engine would buck and lose power and I could coax it home. Now it just dies and will not restart for about 24 hours. Therefore, if I tow it to the repair shop by the time, they get to it; it starts and runs fine for several weeks. I left it at the dealer for three days and it did not act up. I've replaced the fuel pump, fuel relay switch (twice) distributor cap, wires, ignition coil, and oxygen sensor. My next guess is the rather pricey ignition control unit but my mechanic says they rarely die a slow death and usually go at once. Have you seen this problem? Does the ignition control unit sound plausible?  Any other (cheaper) areas I should look at first.  

Thanks


Answer
I would suspect one of these:
Ignition Coil
Ignition Control Unit
KE Control Unit
Reference Sensor
Overload Relay

My personal focus for testing would be:

PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1983 Mercedes Benz 380SL
Part: Reference Sensor
 Note:  Position
Located at front crank pulley.     
F6010-28282 Reference Sensor Beru IN STOCK $60.76  

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=merc...


PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1983 Mercedes Benz 380SL
Part: Overload Relay
P2056-18124 Overload Relay Germany IN STOCK $68.04  

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=merc...