I would also look at putting a plastic grommit in the upper hole where the shock cord comes out of the tiller. It's probably overkill, but I like to ease that sharp edge the shock cord rubs against. I also think it looks nicer.

With this system, when I trail the boat I leave the rudders on, remove the tiller cross bar and bungie the rudders to the hulls in the up and locked position. This holds them very securely and really speeds up your set process.