You are right about that. There seems to be no support from Zenith whatsoever. However, there is a group on Yahoo for these old designs - mainly owners that fly them. They are very friendly and will help you in any way they can.
Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.