Don,

The answer to '1a' is that the foam line needs to be replaced by foam pipe insulation to keep the air in the line at the temp of the cabin not the hot underdash area.

Not sure about '2'. as I didn't understand that either.

Looks like we posted at about the same time.

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1961 190Db retired
1968 220D/8 325,000
1983 300D 164,150