From the pic of the back of the Alternator in Post #24 it did not look like a Bosch Alternator so I did some searching as Member several Years ago had a Motorola Alternator.
Below is the internet address and a Pic of an Alternator labled as Motorola alternator on a Mercedes-Benz diesel
Motorola alternator on a Mercedes-Benz diesel | Flickr - Photo Sharing!
The Ribbed Aluminum Plate either has the Regulator and Brushes or just the Brushes.
You can get parts for Motorola Alternators from NAPA.
Also there is a good chance it is a higher amperages than the Stock Alternator.