The coolant reservoir in my 1982 Vanagon is not holding pressure, despite a
new VW cap.  This was originally a diesel, though converted to gas before I
owned it.  I think the reservoir is the original one and I cannot find a
replacement.  I'd prefer new, if possible, but at this point wouldn't be
picky as long as I can get one in good condition.

The VW part number is 068 121 405B.

Thanks for any help obtaining this part.

Paul