Check out tireskate.com I have read very favorable reviews on these dollies and they look good to me. More expensive than harbor freight, but probably well worth it. They also have skate top that will bolt to their skates and allow the frame to be supported by the skate. For larger wheels, they have frame dollies that bolt to the frame. This stuff could be built but quality castors are expensive so they may be better deal. I plan on ordering some next week. Moved my '37 Roadmaster home yesterday, bought a couple of harbor freight furniture dollies yesterday for $11.99 each on sale. Glad I did because the rear of car had to be dragged sideways to get it out of garage it was stored in. Amazingly the car had not been driven since '52, but all four tires held air. The right front wheel was locked up, but I was able to drag car out of the garage with my truck. After it was moved to my new garage, I put a dolly under the locked wheel and pushed it in my garage with my truck. I'll let you know how the tireskates work when I receive them.
Thanks