Rebuild rudder or leave it?

Today I wanted to check my rudder in the top, around the rudder shaft. I cut out a small piece and see it seems to made with a wood core. The wood closest to the shaft was little bit wet. The wood piece next to that bit was better but with a moist meter I'm sure it would read high figures.

There is some surface rust along the rudder shaft. Something to worry about? Question is, would you rebuild the rudder? Any suggestion what to do? From the outside there is nothing that indicates the rudder would be bad, more than it was rust stain around the shaft where it gets bedded in fiberglass.

 

The first thought that comes to mind is whether the resin in the rudder is Epoxy or Poly resin.

If you burn a little of the scrap, the smell might give you a clue.

The rust and damp wood might just be water coming in from the shaft/glass join.

I see from the photo that the builder didn't make a very robust plug of resin at the top of the rudder to prevent moisture entry.

I would also assume, that the shaft has some protruding "arms" further down the shaft. You could use a stud finder to see where they are.

The decision to rebuild or repair is probably going to depend on usage. I wouldn't take this rudder around the world in this condition, but 3 or 4 years of weekly racing would probably just warrant a repair.