rudder post
Jeff,
I see you have the shims. Cool. What you need to know, is that at the bottom of the rudder post where it exits right above the water line is another shim. It's the bottom shim that's most likely the other culprit.
The play your getting is probably due to that shim wearing out, cracked or completely gone. You need to inspect that area and see if the play is due to this.
Unfortunately if that's the case, the real proper fix would be to drop the rudder post which is a bitch..or, an interum fix you may wanna try to cut the shim in one place and see if you can spread it open enough (without it splitting) to slip around the post. Or, go to a plactics shop have some made with s more pliable compound.
You can use a Stainless steel hose clamp to secure the shim tight around the rudder post pushed up tight to the fiberglas housing, holding it in place. this could help until you get to the yard but it's still just a band-aid fix. You don't want to allow it to continue because you will wear or hog out the hole opening on the bottom.
They make a better 316 s.s. hose clamp now. it's not a crimped type but spot welded. It should hold up longer. But check right above the waterline to make sure. Hope this answers your questions...........
CR