There are generally two primary advantages to joining any Catalina one-design association: 1) Mainsheet magazine subscription; 2) access to websites, some with areas for only Members with a capital M.
So, you're right. Given your OP, I would ask at the C30 website, rather than here.
Many Associations have much more active websites than what the C30 website may have become after all these years. Remember, the C30 association led the way since they were among the first boats produced by Catalina and their association officers did a wonderful job in assembling and distributing the information that they gathered, with over 30 years of contributions to Mainsheet and their website.
I've also found that, like sailing "play it forward" works just as well with boating forums as it does in real life on the water. The more the skippers get involved, the better it is for all skippers, regardless of boat model.