Interesting reading. I'm building my own new rudder this winter. The post at the bearing is 4" solid SS and is machined tapered to 2-1/2 inch at the lower bearing. (skeg mount). The blade is 36 x 72 and 6 inches thick at the lead edge. The shaft has three welded on SS ribs to transmit load tothe skin. Thie old glass was water blistered and the foam core was wet. All together the shaft is about 9 feet long. It took a fork truck to put it in my truck. (400 # plus) Its stripped down in my basement now. I love the smell of resin curing.
My plan will be to build up glass over the ribs and fair the lines over the ribs. Next I will cast HD foam all around and then sand it fair, leaving the glass on the ribs exposed. It will then hang shaft horizontal from the basement ceiling while I form Graphite skin around it.
I found that the designers had arranged a lifting eye on the mizzen boom directly over the emergency rudder access cover on the deck. The mizzen vang drops neatly through and lits me winch it back into position.
I'd love to move the center of effort aft a bit but the skeg mount eliminates this option.