Good, I'm glad you aren't writing it off. I understand about the specialist thing too, I had a "Mercedes factory trained specialist" examine my car and work on it for the first several months. What a joke! That mech was barely ok. I now take it to someone who was around when these cars were new and knows all the little tiny tricks and tips, also a Mercedes specialist.
Point being, All Mercedes specialists are not created equal!
Find a damn good one! You and your car deserve it!