We have just rebuilt our rudder on our 1965 Pearson
Invicta. The only major seal is a standard stuffing box (for our boat it is 1 1/2"). There is an O-ring where shaft passes thru the cockpit
sole but that is just for keeping rain water
out of the bilge
and most likely a standard size o0ring (we hope). Bearing wise stuffing box acts as upper bearing and bronze shoe at bottom of keel
acts as the lower bearing. Not saying yours is the same design but thought I would post what we have since there both Pearsons from the same time frame.