I seem to see so many broken tillers, now i know why Dad always made and kept a spare on our old girl!
It's hard to see with your pic but I'm thinking you may want to modify your rudder stock to take a stainless cap that can support just a strait solid tiller rather than the split laminated system you currently have.
To keep your tiller in top shape coat with UV Varnish and a cover for when not in use.