Just got finished with my wheel mod. I changed up the parts a little based on what others had reported.
I was able to get everything from Amazon.
I went with all 304 Stainless parts as they weren't much more than Zinc.
The 4 pack of casters wasn't much more than buying 2 singles in the heavy duty style and I have two spares.
The Stainless Steel Rod on the first shipment came in a shipping tube which was nice but it banged around during shipping, knocked out the end cap and was lost and FedEx felt I must have ordered an empty tube and delivered it anyway. I was able to work with the seller on Amazon and I had a replaced at my door on a few days.
I have two washers then the wheel then one washer then the locking collar.
Just a quick Pressure Wash and 2 applications of Rust Dissolver Spray Gel, then a quick coat of Rust-Oleum Flat Black High Temp Grille Paint.
It's still drying, I will add another pic after I finish cleaning it up and getting it ready for use.