The supercharger is made by Eaton, not Benz. I have had over the years many vehicles with Eaton blowers. 3.8 Buick,many 3.8 Tbirds, & 5.4 Lightning. If you do not check it every so often and it runs low, you can cook the seals first making it leak. After you lose the bearings, which leads to rotor case contact. At that point, the unit is a gonner.
I just bought a 1999 C230K with 120k on it, I want to check the unit soon. I think everything has to get pulled out to do so. As far as fluid, I have always used Mobil 1 full synthetic gear lube. Redline also make a good fluid that others have used. If you feel comfortable, I would recomend opening the unit. Pull the rotor pack from the case, and grease the rear bearings with full syn. grease. Re seal the mating surfaces with a good silicone type product. I use the aerosol can "Great stuff".
Other Eaton blowers were simple to confirm oil level, AND IT IS IMPORTANT!! With the unit empty and on a level surface, fill plug open. Add oil until it starts coming out the fill hole, thats it. Unless this model fills to the plug hole with the unit in the vehicle, I doubt it though. Do not try to fill the entire unit, more than as I discribed it will cause hydro lock. It happened to me when I bought a persons Whipple charger. He stored it fully filled to prevent corrosion?? I installed it, and it would not run right or build boost. I checked the plug, and all the extra oil poured out, after it ran perfect.

I want to bypass the clutch when desired, by means of a switch and a pair of relays. I hate the lag time before clutch lockup. I guess they made it a clutch because I'm led to believe it's a M62 Eaton on my years, the later years I'm told a more correctly sized to motor M45.