Courtesy of Raimund Feussner, a list member who sent me the information when
I asked about it last year:

1x 251 411 025 C for the bar itself,
2x 253 511 049 for the linking bars between the sway-bar and the trailing
arms
2x 253 511 417  and 2x 253 511 413 to mount the sway bar to the vanagon

I believe it was Raimund who also sent me a .gif file screen dump of the
ETKA picture of these parts.  If anyone wants it, I can send it.  Perhaps a
dealer can order the parts, or maybe our friends in Europe, Australia, etc.,
might have access to them.  You'd have to weld the monting tabs onto your
trailing arms, however.

Chris