Well, its been about 20 - 25 years since I sailed one. Hmmmm. The rudder was made to kick up out of the way for beaching. Possibly the pivot on yours may have loosened. I''d check there first. As far as a
cleat for the main sheet, there wasn''t any. The only thing I can remember that was done was to install a ratchet block on the boom. This was an extra cost option. It helped a lot by reducing the force needed to control the sheet on long runs.
Hope this helps .