just got off the phone with danny at driveline service in san jose
(408-286-0162).  he has done a number of rebuilds of syncro propeller
shafts, and gave me link to a place where they have OEM VANAGON SYNCRO
U-JOINTS.  that's right, folks, he has ordered these for customers and they
are the real deal, identical down to the part number (VW part no. 251 521
000).  they sell for $80.85 plus shipping.

check out this link:
http://cyber.virtualrep.com/megaparts/shoppingcart.tpl?command=showcart&cart
=988823313106366&db=db/products.db&r=82

or, if that doesn't work, go to http://www.megaparts.com, search in their
catalog for your year volkswagon, van syncro, and look under drivetrain.
you'll see "universal" listed, and that's our part.

he says he has not had good success with the neapco 1-0321/bondioli part,
but hasn't used them for three or four years and so they may be better now.
he also has the flex discs in stock for $39.95.

what this means, if you don't count the labor to actually rebuild it, is
about $275 for the parts plus the spin balancing (he charges $65, so YMMV on
that part).  and your driveshaft will be stock vanagon still!

pmail me with any questions.  i am putting in the neapco joints (because i
have them and they've worked for other listmembers recently), but will have
him balance the thing.  i'll tell you how it is working with him, and if he
would give us a group deal on getting shafts rebuilt (for anyone who wants
to), including the flex disc, rebuild, and balancing.  he sends people to
megaparts to get  their own u-joints.

cheers!
bill
'87 syncro westfalia
http://www.scruznet.com/~cikasper/pics/westy
(link currently not working...checking into that)