I think it's possible that the washers in the picture are thrust washers, and the boat was originally constructed without shaft bushings. I used to crew on a Ranger
29 with this setup, basically the rudder
on the entire length of the rudder
tube. It seems a little Mickey Mouse nowadays, but we are talking about boats built some 40 years ago, one 29 feet and one 27 feet. If a significant amount of shaft play has developed over the years, having bushings machined out of plastic might not be a bad idea. I kind of like the soda bottle shims, too.
FWIW, I used the epoxy
repair trick on my old Pearson
26 years ago and it worked fine, but not for the faint of heart.