With older cars, like yours or mine, I found that independent mechanics are by far better than dealers in working with this cars (with few exceptions). Talk to other MB owners in your area. Once you find a GOOD independent MB mechanic (if you like him), stick with him. It will be usually cheaper (fixed right the first time) and you can talk with him directly. Not through a third person(service advisor).
Just a friendly advice.
Good luck!
J.H.
86 300E