Thanks to all who responded to my query.  I have removed the alternator,
and, lo and behold, the two studs that hold the bottom bracket to the engine
block have broken off!

Does anyone know if these are threaded into the block or are they somehow
welded in there?

The one on the left has about and inch protruding, and I may be able to get
that out with the vice grips if it's threaded.  If not... ???  The one on
the right appears to be broken off about 1/8 inch in from the edge of the
block.  That one will have to be drilled.   Too bad the Vanagon doesn't
allow you to remove the rear panel below the hatch and above the bumper so I
could get straight in with a drill.  (Seems to me one of my earlier VWs had
this feature).

Dave in KC (off to work on a stud with the vice grips)
85 Westy
http://members.fortunecity.com/davebaker1