ah crud. :( regulated.

Does this need to rotate, or would it be okay immersed in liberal amounts of grease?

Rotating would be better, but I think it will slide along just fine. It's not like they take a lot of weight or stress.

At any rate I came across another option that for some reason just didn't dawn on me.

Cast another one.

From what I read it takes RTV (which I have in buckets) a good part (I have most of the bits from the old one) and some two part plastic from the hobby shop.

Soon as I clean up and rebuild the broken one I'm going to set about trying to mold my own.

Did this a long time ago with zinc and sand or plaster molds. Actually practiced first using lead while puttering about making fishing weights out of an old section of lead drain pipe. The only reason not to make rollers out of zinc is they have to press over and they could rattle quite a bit and lead would wear out way too quick.

I managed to thoroughly tick off the wife with that approach. Since I had bits and pieces of the part I needed - like you - I decide to use plaster for the mold. Made the split mold with Saran wrap to define the break line, cleaned up the mold, shaped a good sized reservoir for the source plastic (you'd be surprises at how well polyethylene parts from molten milk jugs work ), bored vent holes for the air to escape - thought I had it all covered. Then put it in the oven to cook. Only problem was I didn't know enough to bake the moisture out of the plaster BEFORE using it. Sprayed plaster, plastic, and such all over her nice new oven. Boy, was she steamed! Just glad the oven door was closed when that plaster chunk blew!