>>>the ring with the 4 screws is a potential leak problem. You might want to rebed it if you haven't lately.
You bet. And while under there in that very confined space, put double nuts and lock washers on those 4 machine screws. They tend to loosen under the working of the rudder post, and tightening them is a two-person job best done as infrequently as possible.
More on this particular fitting:
Look at the top photo above and note the wear point on the cap.
This was the result of the top of the rudder post wobbling unseen under the cap, and getting so far out of true that it gouged the cap. Unscrewing the cap was difficult because the top of the post was jammed into it.
You can't see this happening by just observing the plate. The plate never moves and its bedding to the deck remains firm.
AS it happens, those four machine screws not only hold the fitting to the deck, they also hold the (separate) top bearing of the rudder post.
Should they loosen, the deck plate remains firm but the bearing underneath drops a bit and wobbles unrestrained. And with it, the rudder post.
In fact, if the deck screws are loose, when you go belowdecks and put your hand on the bearing, it may be completely loose and about to fall off.
And you'd never know it from the cockpit.
The test is whether the screws can be easily turned with a phillips head--or if you notice them moving when you turn the steering wheel.
The fix is awkward but easy--just tighten them up.
