Ahoy Ian,
In my opinion there would be no reason to change away from the wood boom just for a change. If it is in good condition, and you are satisfied with the weight, and everything works satisfactory then keep it. It could easily outlast you.
About the rudder shake. Hmmm. It seems that most W-32's have a little. If not all. After about 40 years, people are still guessing as to what causes it. Certainly it is a combination of things. The boats with the SS gudgeons and the boats with the fiberglass gudgeons both exhibited this phenomenon. Part of the condition would be caused by some looseness between the gudgeons and pintles. I reduced some of my shaking by shimming the gudgeons and making as tight a fit as possible with the pintles. It would be nearly impossible to get three sets all perfect to a "machined" tolerance. Another source would be the constant chaotic water flow over the rudder as you are motoring. The rudder is about 10' long and that is a lot of area with which to pick up some turbulence from all the different water flows at different parts of the system.
I have not experienced your boat and rudder but I have sailed on at least 14 W-32's. All had rudders that exhibited some degree of shaking. It has never been a concern to me. If possible get another Westsailor to go out on your boat and get their opinion. Or go out on theirs for a comparison. Keep us informed
Good Luck, Dave
