If you are looking for a shop try -
Carl & Steve - Really nice guys. Both enthusiats with modded cars (560 SEC & 500e). As well as being really good mechanics they know there modifications as well.
6318 Sepulveda Blvd.
Van Nuys, CA 91411
- or -
Mr MB Motors
Tarzana, on Reseda just south of the 405
Enrique - Mercedes mechanic for over 40 years - likes to keep it "stock"
Both are trustworthy and do good work. Though a bit of a dirve from PV they are well worth it. Too many crooks out there! Both will let you know what REALLY needs fixing and what can wait. Both price there work fairly. Both Carl and Enrique have M119/W124s and are very familiar with the car.