Not to drag this out, but it might be helpful to someone on here. I went out to the boat yesterday to finish up my cutless bearing R&R. That's what started all this. Thx for the John Duramax referral BTW. Anyway, I did a closer inspection on the rudder bearing situation:
The 2 bearings inside the rudder post hull 'tunnel' seem to be intact. The broken one in my first post is identical to these two, but it looks like rides under the steering quadrant, between the quadrant and the cockpit 'floor'. I think it acts more like a spacer to give the quadrant clearance. Underside of the quadrant casting has a circular groove for the bearing. Then the bearing and two thin plastic spacers set the height of the quadrant and rudder post. This closes the gap between the bottom of the hull and the rudder. Does this make sense? I can't find a drawing to confirm this.
Meantime, I think maybe Hunter just used the same bearing used inside the post tube for a spacer under the quadrant. That should mean a simple UHMW or Delrin part with the correct ID and OD, minus all the groove should work fine. The OD wouldn't even have to be that precise. That should simplify getting one fabbed somewhere.