On Thursday, May 9, 2013 4:45:42 PM UTC-5, Jim wrote:
Did you consider Rollerblade wheels? They *look* about the same. -Jim

I made some for the Cobra trailer I am working on. Just got some 3/4 inch diameter nylon bar, cut off a quarter inch thick slice, drill a hole in the middle for the bolt, and install. Of course, it works much easier when you can remove the parts from the sidewall first...