Just purchased a 1978 Oday 20 and need to rig for single handed sailing. The current jam cleats don't secure the jib sheets. Can I add cam cleats to the rim around the sides of the cockpit (near the jam cleats)? I would have to use screws as there is no underside access to use bolts and a backing block. In addition, I need to install a cleat to secure the pendant/line used to raise the centerboard. The original horn cleat has been pulled out. Can I use longer screws to reinstall? Basically, is there wood under the fiberglass in the areas I need to modify/repair.