I trailer a car shell like yours from panhandle in Fl. to Plant City Fl. on dollies similar to what you have. I had one collapse on the rear and kinda messed up the quarter panel. But the second issue is unloading it.
What did you haul it on? Florida roads are pretty good and flat! Those US car tool dollies are pretty darn stout! My car had a rough ride up I-85 and back from north Georgia to Spartanburg. That road through Greenville was pretty bad. The car never moved either up or back and more importantly back! I used grade 8 bolts to fasten them to the body.
The car was transported sever times that way and twice on roll back while in Spartanburg. No issues at all.
