Ive got a copy of the wiring diagram for my car but most of it will be removed and replaced with the toyota stuff. Thats the easier part for me. The diagrams came in an aftermarket manual called Mercedes w124 1985-1995 owners workshop manual. It has a black and teal cover with a colour picture of an update w124 in the middle. It says published by technibooks but has brooklands books written on the back. Its a limited manual, alot of things arent covered but the ability to have the diagrams in front of me in fold out form is very helpful. They appear to be copies of some factory diagrams and are across 3 a4 pages.
Ive also got the factory cds for my car, pain in the ass. For one im not going to take the computer into the garage. Secondly the instructions dont translate too well. I was removing the plastic chair backs of the front seats to install head rest monitors. The instructions reads: undo the two screws at the bottom and pull out laterally. What this is in proper english is attempt to undo two screws that are as tight as engineeringly possible and pull like all buggery.