I don't know if this is current but this used to be the source of the official Mercedes Manuals on CD. On one side it the computer operating systems the msnuals work with.
Star Service CDs and DVDs
The free W116 site works and another site said there is some useful stuff that crosses to a W115 in it. If nothing else you can see the format of the official Mercedes service manual and how it works
http://handbook.w116.org/matrix6.htm