I've got a '94 E320 with some very very similar problems to yours (filon) it seems. How was your's running though? Was the idle just rough all round, high, missing or what? I've been CURSED with a high idle problem. (BTW you haven't spent nearly as much sniffing your bugs as my pour soul, OVP, MAF, IAT, O2 Sensor, Idle Air resonance valve, coolant temp sensor, reman ETA and a few other odds and ends... not counting the new wiring harness a few year ago)
I get the error code for "idle control inoperable", do you think that I may be suffering from similar ETA woes as yourself?
I haven't found any vacuum leaks, but seem to have an abnormally high vacuum in the crank case for idle (15-1800 rpm).
Any and all thoughts are appreciated.