IMG_2598 
The culprit seems to be the compressed paper gasket material which dries out if it sits for a while and then leaks.  Cork gaskets were recommended as a replacement.  Unfortunately, cork gaskets were not available.  So I did a Google search  and came up with Nitrile Rubber gaskets from Wahoo Products.  For US$9.00 ea. +50ยข shipping it was worth a try.  Here you see the standard compressed paper gasket on the left and the nitrile on the right.
 
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