Hey Ken,
That sounds like a good post (pictures of cut up sections of a hull), I've been wondering about thicknesses myself. When I've been below under the cock pit seats, I can see light coming through the hull (opaque sides) and appears thin, I was wondering if it was just my boat or all Catalina 22's but she floats well, so far, while sailing, I've only found one leak and that's the keel lock bolt and I've read that grease will resolve that, rest is rain water leaks sitting in the yard. I'm sure I'm not the only one on the board that's wondered about the thicknesses.
I know one thing, I've been reading about how thin the glass is around the cabin top, I'm pretty thick around the middle and my deck has not given one fraction of an inch that I can feel.