Have you tried a Google search(es) on the topic? Unless there is an owners association Google is usually a sure bet to find stuff, although you may have to wade through a lot of hits.
We had a pop top on our Catalina 25, two struts per side and it lifted up and was supported by a fitting that slid in the track on the back of the mast. Seems to be what most pop tops have.
Yes, sure have. There are very few photos of the pop top up close. I've watched videos of Cal 25's for sale as well "just in case". Our friend had a Cat 25 - he said it is substantially different from the Cal 25 pop top. Unfortunately the Cal 25 Owners Assn forum does not appear to be active. I even sent a note to their webmaster asking for information. No joy. :-(