You're the only other person that has had a crack on the rudder arm. I saw a little more play in my rudder (once), and when I drilled out the rivets to re-seat it in epoxy, I noticed a small crack at the end.

Good thing is that you can cut almost 2" off the rudder arm without affecting anything (as long as you shorten the other side) if I recall correctly.

After that, I got in the habit of drilling and re-riveting a lot of things on the boat before each season. If nothing else, it made me "one with the boat" more.

And I'm not sure how you can address water coming in from the daggarboard trunks. The only place mine leaked was the deck lid seal, which I just filled with 5200 when I found it.