I would think that as the number of hulls multiplies you could form a group of your own. You will need someone that has the skills to maintain such a site that is willing to take on the workload. I belong to the C34 association and find it invaluable. What you get is usually quick answers to those questions that sometimes the dealer has not figured out as yet. These guys are quite amazing in their detail and archives over the years.
If you have the abilities to create and maintain a site, go for it. If not, join the 30, or 32, or 34,or 36 site and when the numbers are right create your own association. Lots of Catalina parts are similar if not interchangeable. Problems that happen on a 309 are probably happening on other boats as well. If nothing else, the association has people that probably know WHERE to find the answer to your question.
OH, and the dealer can get things done, but Frank still makes the decisions. Knowing what is happening in the fleet does carry weight.