Rudder bearing

[jesperht]

Have some slack in my rudder bearings, and would like to get it fixed, but it is not just a change of bearings, since there are no bearings!
The rudder is attached at the hull, here there a no problems, but the lower attachment are. The axis is 50 mm stainless steel, running directly in a big bracket made of brass.
The brass bracket consists of two parts, a very solid part connected to the hull, and another small part connected to the big part by two M10 bolts. Between the two parts is the 50 mm axis. I have a slack of 1 mm appr..
My thought is to take the brass parts to get mascined to a bigger diameter, leaving place for 2 half moon shaped bearings, having a bunch of these made, so i will have some in the future. But what should they be made of? They should not be worn to fast, and corrosion must be avoid.
Or maybe someone has another suggestion?
The previos owner had reinforced the rudder, making it thicker than original, maybe this is causing exesive wear?