The CD will have most of the information you seek. It will have all of the wiring diagrams, you will just have to print them out.
If the engine hasn't had synthetic, I'd not use it. It will cause the head gasket (that is already weak on the 104) to start to leak.
You may have to get the windsheild replaced. Don't sweat it, because we have them done for around $500, I THINK, (DON'T HOLD ME TO THAT PRICE THOUGH.)
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS