Matt,
I have advertised in the “For Sale” section a bunch of #4 Sierra valley wheels which are 1.290" in diameter, .250 thick, with no protrusions. And can be had with a delrin bushing for .125 axles made in drill rod or stainless steel and 2.5" long.
These are blackened Sierra Valley Ent. wheels brand new and never used. I will swap out the bushings and insert the new axles.
How many do you want? $3.00 per axle. Large numbers would cause shipping to be an additional item.
Barry