I have had the car towed from Foreign Motors West in Natick, MA to Hatch & Sons in Wayland, MA. Ken Hatch seemed to have the same approach advocated by Larry and Benzmac. He felt that he could tell pretty well if there was internal engine damage by removing the coolant and turning over/running the engine for just a short time to listen for any weird noises. No noise = probably just needs a head gasket. It is also possible to borescope the #1 cylinder to see if it is scored. Mercedes dealer was not interested in doing this much diagnostic work so I fired them. Thanks again to all who posted.