There is maybe or probably a "washer," likely Delrin, on the shaft. I don't know that it matters much.
Rudders can float, so probably it's to prevent contact of rudder blade and hull.
But the quadrant, or other factors, often fix that distance anyhow.
As for a lower bushing or bearing, I don't think there is one. The bottom of the rudder tube sleeve suffices.
The top of the rudder post is held by a greased bushing. There is a packing gland atop the rudder tube.
The Ericson rudder installation is intentionally simple. It relies on lots and lots of grease through the Zerk fitting provided.
Some models have better illustrations in the owner's manual than the E38 does.
Ericson 38 rudder install