... here's a pic, sorry, one of these days I'll figure out how to post larger format photos. I'm not at all sure what was there is Delrin. But looking for replacement alternative and on the MMC site that seemed like a reasonable choice. The Delrin Washer isn't pinned or tapped into anything. It is between the bottom of the alum Stop Collar and the top of the bronze Stuffing Box Cap, it simply provides a bearing surface.

Looking at this photo, from the bottom up, we have ... Stuffing Box. Then the whiteish 1/4" thick plastic Washer I want to replace, you can see it is broken, and no longer separates the Collar from the Box, so, I have metal on metal ... not good ... my Rudder has dropped 1/4". Then the 1.5" tall Alum Collar with white paint flaking off, I should replace this as well because the bottom is now rough from grinding against the Stuffing Box (which is not damaged). Then the space on my Stock where my Tiller Arm goes, I had it off when I took the photo. Then my Quadrant. And then up inside that Housing glassed into the cockpit sole is a bearing that the Rudder slips into, you can see the set screws for the bearing, and you can see some grease from the bearing at the top of the Stock.

Thanks ! Cheers, John