Re: AMF Puffer Restoration
You can look up the properties of Starboard. It's similar in weight to most marine woods. It is very easy to work with and cuts super nicely. It requires no finishing, but doesn't look as nice as wood.
I think it's a great option for the rudder. It might be a little bit more flexible than similar size plywood, but the rudder on dinghies is usually small enough that this isn't a concern. It won't warp or rot or swell or do anything else the wood core rudders do.
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior