Well, its been asked at least a billion times, more or less (bg): Where can I find data for my MB repair. Well the definitive answer is here:
www.startekinfo.com
We may be cheaper, but not nearly so visual. Lots of bugs including the fact that I spent near a half hour at work trying to buy one of those $300 months only to give up. Later at home I tried for a day and got through. Looks like I got my Saturdays reading defined.
An interesting, humorous bug can be found without even entering the site. If one clicks on the heading "search" a description of that function comes up in LATIN if my junior high scool education isn't failing me.
All of the diagnostic manuals are there and they list ETMs for every chassis from202 and 140 onward (all the ones not currently covered in CD form). None of the ETMs worked for me. I got runtime errors on every one I tried. The DMs seemed to work fine. Lists and lists of service bulletins reminded me of an ebay search. They are only gathered by date so its about impossible to look for a specific topic. But they were interesting reading.