I would just go to a local muffler shop and have them custom bend you up a
new pipe.  Cheap, easy, and relatively painless (compared to dealing with
dealers).
Is your van legally registered in the US or is it here under some type of
temporary certification?

I was thinking about importing a bunch of 1.7l diesel Vanagons several months
ago and some were of the same vintage as yours (89).  Almost all of the
importer guys I spoke with thought it would be either impossible or very
expensive to import a diesel Vanagon that was a later model and had an engine
that was never sold here in the US (like your 1.7l).  VW only sold diesel
Vanagons here in 82-84 so getting an 89 through the DOT would have been a
nightmare (so I was told).

Thanks,
Ken Wilford
http://www.vanagain.com
John 3:16
Phone: (856)-765-1583
Shop:   (856)-327-0027
Fax:     (856)-327-2242