Not satisfied with the noise of the original part or the design of other created options I found, I designed this Z-axis top plate/bracket to improve it. It is simple and clean, and that is how I like it. The bearing is interference fit so it should not move. The bearing is a standard inexpensive skateboard bearing. Just press it into place and go. Note to those concerned about securing the threaded rod, it is not a tight fit at all within the inner race of the bearing. The hard steel of the inner sleeve does not squeak or even move as the x-axis move up and down. The bearing is essentially useless, but I guess it cannot ever bind because if it does then the bearing would work.
I created it in 123D Design and included the original file for reference. BTW: the holes lined up perfectly, so no concern there.
A little elephant foot at the bottom of the bearing hole is not necessarily a problem. I would not clean that up.
Chased some holes with a drill bit to make the rods and screws fit, but otherwise nothing to worry about.
Knowing the parts were made to metric specs, I measure and defaulted to the nearest millimeter. It worked perfectly as I stated.