Here are the pics of my alterations/customisations to the deck fitting for the top end of Omega's rudder shaft.
It's simple but strong (like me!). The new plate is bolted to the deck. The plate contains a delrin bearing inside the tube which extends and protrudes from the top and the rudder shaft is passed through the lot. A collar, also containing a delrin bearing is slid down over the shaft and screwed onto the shaft at which point begins to take the downward load of the rudder. The two delrin surfaces rub on each other creating a low friction bearing and no more metal on metal! The original tiller casting is then cross bolted to the top of the shaft to complete the install.
Is much stronger than the original and is more fail safe to boot. The entire tiller assembly can be removed without the rudder falling out the bottom of the boat and itself becomes a backup stop to the collar should it work itself loose for whatever reason.