Looks like a cool vehicle, not something you see everyday.

If you can find the VIN, you should be able to get the rest of the vehicle data. I was lucky that my truck came with the original data card which has numbers for the motor, chassis, trans, axles, etc etc.

Anyway, I was able to get a manual from http://stores.ebay.com/Schiff-European-Automotive

Also, I have had good luck with parts from http://www.eurotruck-importers.com/, ask for Steve

I had quite a time figuring out an oil filter for my OM314 engine (L508D truck), but I got some good info from http://sct-germany.de/Catalogue/main_eng.html Go to the "Industr" section and select Mercedes, then various engines show up (not sure which one you have)

With paitience and a good internet translator you can get quite a bit from www.ebay.de or google.de

What speed can you get from your vehicle? What wheel & tire size?