I've recently acquired my first VW ('86 WestyWeekender, 99k), and need
to take care of a few items.

The compartment under the drivers seat contains not as I expected a jack
or tire iron, but another battery which appears at initial observation
to be connected into my system. Anyone  know how this setup works? Does
it function as a backup in case the one under the passenger seat fails,
or just give me more duration for running appliances?

Also, wondering the best place/price for:
the jack
one missing section of curtain
a small white plastic washer-like item (one of 2) located at the end of
the cranking arm mechanism that lifts open a little ceiling vent in the
center of the pop-top.

Any suggestions/resources appreciated.
--jp