Rudder shoe
Thanks for adding the pic. That's a big help. Looks like you do have a bit of a problem there and what you'll need to do is buy or fabricate a new "rudder shoe" for the bottom of the "skeg". If you're fairly handy with tools and have done a bit of fiberglass work you should be able to tackle the job yourself. If not, then any good yard should be able to do it. You'll have to do a little internet searching but I'm thinking a nice bronze casting should be available that would do the job. You'll need to do some glass work to fit it to the skeg in addition to boring it to fit the rudder pintle. A local welder/machinist who's good with stainless could also probably make something up that would work.