Vertical slop fix
My 37 cutter also had a lot of vertical slop. If you look at the top of the rudder post, there is a collar resting on a plastic block that is screwed to a structural shelf. I added a second plastic block under that shelf, then bought a propeller shaft zinc the same size as the rudder shaft, and clamped it under the new plastic block to limit vertical play. The zinc acts like a thrust collar to limit the play. I have not had any problems with ti slipping down the shaft.