very stiff rudder and tiller

On my 1966 hurley 22 I find that the rudder is almost impossible to move. It improves somewhat if I move the rudder by hand a few times. The old owner said this improves when the boat is in the water. I am dubious.

The rudder on this boat is inboard. To the best of my knowledge the rudder post runs through a galvanized steel rudder tube. This is an issue on hurley 22's due to rust over time of the rudder tube. Mine is not easy to inspect, it looks like there is a little rust-- would this cause the problem I am having?

Other possibilities that I can think of are:
1) bent rudder post
2) worn bearings?
3) lack of lube in bearings with lots of grime and rust?

Any suggestions?

How is water prevented from entering the rudder tube?

The hurley 22 owners association offers this:
Hurley Owners Association - Rudder Post Problems and Repair