I have a 34/35 Snowgoose and had one rudder delaminating so I took it apart. It was actually built in 2 sections and then glassed together. But inside was only plain
steel and badly rusted. I cut it all out and replaced it with some stainless and glassed it back together.
BTW, the mount for the aft
steering box was also plain
steel and nearly gone when I replaced that with SS as well. plain sttel exposed to
salt air was just crazy thinking.