Lint to ICV at fastlane with pic:
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1Q1172JL21Q216YDXW&year=1985&make=MB&model=380-SE-001&category=C&part=Idle+Control+Valve
The hoses on each end can be bought pretty cheap. Try:
http://www.mercedes-benz-parts-direct.com/
The jumper hose I referred to goes between the two hoses on each end of the ICV sort of like a bypass. Didn't have it on my 85 380SE. Indie added it by drilling into 2 hoses at each end of ICV. Improved idle. Last time I looked at a V8 (87 420 SEL) this bypass hose looked like it had become a factory stock item. If you look at the photos of the hoses for the ICV for an 87 420 SEL at:
http://www.mercedes-benz-parts-direct.com/
you can see the jumper (hose connector) and a photo of the two ICV hoses with a place for this jumper to plug in. I don't recall seeing this arranagement on pre-87 V8s. Its possible the 87 ICV hoses and jumper will give you the mod on earlier V8s. Was hoping one of our resident gurus would have popped in by now. I am not an expert on this. Just passing on what I have seen.