The rudder arrived in perfect shape and I had the boat hauled, put up on the hard, rudder installed and put back in the water without a problem. I went sailing today for the first time and am amazed at the difference in boat handling.
I can pretty much categorically state that the previously repaired rudder damage must have been caused by pretty severe contact with ground, severe enough to have caused some sort of twisting or bending of the rudder. It might not have been visible to the eye, but I did notice a 1+ knot speed difference between port and starboard tacks as well as a significant difference in angles to the wind that I could run. I attributed this to other factors, but today proved differently.
I had 2 people on board as guests who had never sailed before, so I didn't run the boat through all her paces. I started off with the 3rd reef of the genoa and the rough equivalent on the main since the weather report stated 18-20 knots of wind and I didn't want to heel too much for my newbie guests. The wind ended up being 25knots constant with gusts over 30 so the reefing choice wasn't a bad one. I've sailed in identical seas and wind with the "old" boat and the newly ruddered one sailed 1knot faster on ALL points of sail, plus the sails were well-balanced most of the time, with the old rudder I would have had to use very significant amounts of weather helm for the same course(s).
All in all I'm very happy with the "new" boat and think that the mystery of the rudder problem is closer to being solved - it would seem to be more of a previous-damage-through-ground-contact issue than a systemic or engineering problem.
Something missing in this picture...
4 layers of primer (Note Morgan Freeman's "Afrodesia" in the background)
Then 4 more layers of antifouling