Thank you Arthur
I appreciate your expertise. I can't really say that I live an "extreme environment" as I'm virtually a neighbor of yours (Francestown, NH). The car in question is a new 300SDL for me that I purchased out in San Diego and had trucked to Boston. The body and interior are in great shape but mechanically I've developed a sizeable "punchlist" that I'm working my way through. It now appears that I will ultimately be facing the all too common head gasket/head replacement project sometime in the near future.