Who says you can't post links? There is a box for URL's right below the Comments box whenever you reply to a post.
Forums are supposed be be here to help people. No forum contains every piece of information for every tractor ever made. Any forum that prohibits sending people to other locations to get the information they need are not helping the very people who come to their site for help.
There is a Haban group on Yahoo. Got to Yahoo and then to Groups and search under Haban. The descendants of the owner of Haban have posted information on that site.