ZTR428 caster wheel bearings?

Hey all. Just picked up a 1987 ztr428 to mow around all of my apple trees and landscaping. I'm having trouble finding the right part so I'm hoping some of you can help.

One of the front caster wheels is loose/sloppy. In comparing the two caster wheels, one has ball bearings in between two "curved washers" for the lack of a better term. I can see the ball bearings that are sandwiched between these two washers but the other caster wheel has no ball bearings at all. Seems like a silly design to have the bearings open to the environment but I guess it'd be easy to service and check on??

I am sure I can get some ball bearings of the right size and throw them in the washers but I feel like I'm missing something with this unit. I've checked out the parts diagrams and I see that the caster yoke is labelled as 1212; I've searched the part number but it just shows the yoke weldment and it doesn't show a side profile shot to see if there are ball bearings in the washers or not. The price is also astronomical. I see the wheel bearing that goes on the wheel's axle but not the vertical caster axle. Should I just throw in some ball bearings and tighten her down?

That is exactly how they are built. Get some ball and put them in and grease through the zerk and start mowing. It is a bad design but it is what you have to work with. Grease often it will push out the dirt.

Hmm. Took it apart today. the balls in the complete one are loose and the two plates aren't held together very tightly. The one without balls are completely loose. I haven't tried this but I'm hoping that tightening the nut on top would pull the yoke up and close the gap on the plates.

In any case, if I can't tighten the plates together then I may opt to just weld on a new tube and use a more modern design with flanged bearings and bushings. Has anyone gone this route? Tips/tricks?