You could try it, but the rudders probably wouldn't be class legal anymore (too thick). A lot of hand work, too in getting the finish smooth (critical on the 16). Practically nothing sticks to Lexan, so I wouldn't recommend it on them. The PVC rudders have a nasty tendency to snap just below the rudder casting.

Unless you're really into experimentation, I'd just get the foam core / fiberglass rudders and be done with it. (Less time in the shop, more time on the water.)