Why not do it like the factory did, and it will be good for another zillion years? Catalina Direct sells a kit for this very job.
The folks at Catalina Direct go out of their way to find the products that help us fix, repair, and maintain our C-22's,(and other Catalina boats), why experiment? Do it right the first time and you'll only do it once.
http://www.catalinadirect.com/index.cfm/product/1054_373/aluminum-window-reseal-kit-c-22-cp-25.cfm
They have also been a huge supporter of our C-22 Association for many years. One back-scratch deserves another......
Good luck on the project,
Don