You just need the W126 CD-ROM. Try your local dealer, if it's not showing online. The 126 CD includes all models & years of the 126. The only other option is to obtain the full set of 4 or 5 printed manuals (chassis, engine, electrical, and climate control) since the WIS doesn't include any info on the older 126 with OM617 engines. Unfortunately, the print manuals are nearly worth their weight in gold. Could cost you a couple hundred bucks for a full set.
If you still have no luck finding what you need, drop me a line, I may be able to help out...
