I would second that. I have used Hatch and they are well versed in the older Benz's.They are not shy about charging you $$$. They also offer loaner cars so if you're coming from NH you will have a car to use.
I would definitely NOT recommend Koko's in Cambridge. Son of a ***** ripped me off. Didn't do the work he and I specifically discussed and misdiagnosed old fuel return lines (diesel smell) that I figured out on my own.
Wouldn't mind hearing of a reasonably priced shop around Boston for my non essential repairs, ie: sunroof, cruise control amp.