Just to save me a whole lot of Googling, what are S-Class and C-class - everyday Merc sedans, 4WDs, ??? I have no idea what they look like- thought maybe a wrecking yard (or as you guys say "junk yard") may have something around if the diff blood lines are old enough.

Still have the computer problem - that could prove a little bit curly.

I work with a couple of guys with Skylines - they have a 200km/hr speed limiter on them - the rear end ratio is in the region of 4.3:1 - damn those autobahns. Without them, the MB reasoning may have been different.