Flat-free glider tail dolly wheel

Just finished this conversion.
Found a flat-free wheel and tire at the local Tractor Supply Co (tractorsupply dot com). SKU 3553230 "Never Flat Tire, 8 inch". It's rated for 220lb / 100kg and has a 2.50x4 tire. It's soft enough to provide some shock absorption.
But that wheel has 5/8" bearings, and the bearings are offset to one side for installation on the end of an axle.
That can be fixed with two 1/2" ID, 5/8" OD brass bushings (the ones I found were 1 1/4" long) and a third brass bushing 5/8" ID, 1" long as a spacer to the other side of the caster fork. Your caster may require a 1/2" flat washer on the opposite side to the bushing. All available from True Value Hardware, bushings $2.40 each. A 3" brass bushing from McMaster-Carr is a better way to go but $10.50. Another method, 1/2" bearings to replace the 5/8" in the wheel are about $4.00 each, still requiring a 1" spacer.
_ My total cost was about $23.00.
It's "hecho en chine" but haven't found a domestic 2.50x4 "flat free" yet. Anything wider won't fit the standard tail dolly casters. If anyone finds a more appropriate wheel, please inform.
Jim