Like others said, I'll not offer any help on getting this out.

The bus will run without the sensor hooked up.  There is a fallback mode
to keep you on the road if the thing fails.  My '86 went from 24 mpg
to 16 mpg with it unhooked (my problem was that it was working, but my
exhaust pipe had a hole in it).  Any three wire one will work fine --
just save your connectors to ad to the new one.  The VW ones come with
the right (and apparently unusual) connector.  A single wire O2 sensor
will work as well, and probably even pass smog when good and warmed up.
They need to be quite hot to work (600' ?), and the other two wires
run a little heater inside the sensor to bring it up to temp quickly.

Replace the bolts with stainless steel.  VW should be heavily critized
for not using stainless to start with for this stuff.

BTW, somebody else posted a query about stainless exhaust availability.
Any answers?  Maybe we should all get together and order a batch of these.
I'll take two, one syncro, one plain.

malcolm