New rudders can be ordered, but are around the $1300.00 mark.
My 1975 had a worn shaft, about .020. Even with new bushings it still had slop.
On Dan Pheiffer's site there are directions on building up the runner shaft with west system epoxy and grafite powder. Did that three yrs. ago and it has been good since.
Not a fancy boat by any means, but sails great.