I am really surprised you have not found anything on the Cal 27. I bought one 3 years ago but before I did I found tons of stuff on the boat, including the owners’ manual online. The Cal 27 MkIII is a wonderful boat. We loved our time with it. We sold it this year after we bought a bigger boat. If I was less than 6’5″ tall we’d still have it. We still know the new owner and are friends. He has invited us to take the boat out any time we want. We have gone cruising together on Lake Michigan.
Just try looking for Cal 27 manual. I’m sure you can find what you need.