Cracked rudder, repaired by previous owner-how much should I mess with this?

I’m looking to refinish/repair this rudder (and my daggerboard while I’m at it). I have a new tiller and extension ready to go.
I’ve read so much about this here-thanks to everyone. I’m hoping someone will have thoughts on the following:

-the blade was cracked all the way down. It has been repaired with a wooden dowel in one location. It seems to have worked, as there is almost no play in the crack at that end. Obviously, as you move to the far end, there is more movement/need of...

Cracked rudder, repaired by previous owner-how much should I mess with this?