I ended up buying a kit from these people
Rebuilder in a box for my Dodge Cummins. Perhaps the vids will be useful and/or they may have parts for the MBZ.
The new Bosch voltage regulator was bad out of the box on my SD but I eventually found a good one. I forget whether the unregulated alternator puts out a high voltage but remember that something I found when testing indicated that the voltage regulator was at fault. Also, make sure that the glow isn't stuck on as that can pull the nominal alternator voltage down. The parts store condemned my regulator when the car was glowing. You have to be certain what your test results mean or will install incorrect parts.