Rudder

With John's suggestions and help with the metal work, a rudder assembly is shaping up:

I had made the blade with the top rounded side-to-side. John showed me how to make a groove on it, to direct the down-haul line and keep it from jamming between the blade and the cheeks. I first glued down a piece of small rubber tubing, then used milled glass fibres in epoxy to make sides around the tubing. When the epoxy had kicked, the tubing came out and the sides were smoothed up, leaving a nice smooth groove in the top of the rudder blade. 

The centred hole for the original pivot will be filled. This is a much different rudder!

(The blade's surface was contaminated in places with something that kept the paint from setting up, so I scraped it off—that's why the paint is uneven.)

The tightness of the pivot bolt determines if the blade sticks in the "up" position. There will be a horizontal bar on top of the post, which the steering lines will connect to, and a pin through the post at the bottom, so the rudder can't come off inadvertently.