Welcome to the "Seattle Contingent" Trina.  I think I've seen the very
Carat in West Seattle that you mentioned and asked the same question but
go no response.  I'm in Lynnwood but get to West Seattle frequently, I
grew up there. On the oil filler, give Rudi a call at Schaffner Motors
in Lynnwood, he might very well have a user part for you, 425-778-6900.
If you camp in your Multivan, you might want to check out the
WetWesties, wetwesties.org  a NW VW Camping group that gets together
several times a year in Washington and Oregon.