Good job! You fixed that tiller very well! It's a pity you've come in underweight, but it's a common beginners mistake. Been there myself for ages... Del the kitty has given you some excellent advice. He is spot on. I noticed that weak spot on the right limb as well, near that funny pale triangle on the wall. This spots still bothers me a bit. Please inspect it closely; is there a small knot, a chrysal on the belly, or a splinter ready to lift?
I can't judge from the pictures: have you rounded the corners on the back? I don't think you should change tiller anymore, but rounding the corners on the back is crucial. You'll loose only like 1 or 2 pounds, while it doesn't affect tiller (since you remove wood along the entire length of the limb). The rounded corners mean there's less chance for splinters to lift.