These parts are not so exotic, at least in europe. They show up from time to time in the german eBay and I got one from my local bike shop. The derailleurs are not for cyclocross but were Campagnolo's first try to enter the Mountain bike market 1988:
http://home.t-online.de/
Dirk
Dirk Feeken Heidelberg Germany
--original message --- From: <chasds@mindspring.com> Subject: [CR]ebay outing: for the CR denizen who has everything... Date: Mon, 23 Dec 2002 20:47:02 -0500
Check this out:
Final version of the Rally derailleurs, for cyclocross bikes, apparently.
I have never seen these before. Very cool, though, I think.
Charles