humm had a look at my stock air box (dont use it anymore) and it has traces of oil vapor on it (which its supose to)... I think yours has way too much
3 hoses explained
1st one - this one connects to the airbox. in theory it should be "sucking oil vapor" from the oil seperator.
2nd one - the thin 3mm rubber hose going to it. this pushes air (boost) from superchager in the oil sperator spiral to help seperate oil/oil vapor
3rd one - this one connects down to the dip stick to let oil drip down back into the engine
in my case when i got my car a while back hoses 2 (complelty degraded) and hose 3 split apart due to its location near the exhaust area. i didnt use benz specific parts (again couldnt find number). took it to an auto store and got some rubber hose cut up. fitted fine
i think in your case hose 2 has a split somewhere and its not doing its job seperating oil/oil vapour and its being sucked into intake... have a closer look. can take it to an auto parts store im pretty sure its just plain 3mm vacuum hose. then zip tie it away from the exhaust area as you can to anther hose nearby.
would be a good idea to clean out the intercooler (ive done it). (search around). not a hard job at all. only tricky part is taking off the front bumper (once you have done it once its easy...)
i know oil vapor has to be vented BACK into the intake but what i DONT get is why did benz to chose to do this thru the supercharger/intercooler/MAF... wouldnt it be wiser to vent it into the intake manifold bypassing the lot incase of say failure??!