I couldn't find mine either, but i think its on the registration papers, I have to take a look.
Have you had yours yet in the water?
I have done some major re-modeling on mine and got a lot of help from here if you need info, let me know I can help ya if you like.
ps. I passed a Catalina 22 a few month ago on my rusty Cal 21, what a feeling......LOL.