The Nolan dolly will work, but I didn't like the design for 2 reasons:
1. It's too low for tall guys like me to work in the car without spilling my beer.
2. The side support rails cover up too much of the vehicle underside side supports to do work on the bottom.
So I went out and bought me a few sticks of 2"x2" steel tubing (it's cheap), and welded up this body dolly in about 4 hours complete. It puts the car high enough to work on the bottom and sides, yet I can still get to the center areas. It supports the body under all the body mount points with a pedestal, so everything under the car is completely accessible. It keeps the car rigid enough that the doors can be opened, and I can work inside the car with the car on the dolly.
I didn't work off any design - I simply measured the distance betweeen the body mounts with a tape measure and made the dolly that size - very simple and easy to do.
Lars
The diagonal front and rear supports keep the body from sagging, so doors can be hung, aligned, and opened without the body drooping.
Detail of rear angle support - simply props up underneath the rear body mount (both sides) to provide plenty of support. Nothing is actually bolted to the body - I have good gravity in my workshop.
Dolly holds the body high enough that it's comfortable to work on the body sides, and it's easy to get into the engine compartment area for working on the headlight bucket system and the firewall.
That's me doing final placement and welding of the forward angle support - it comes up under the forward header bar and supports it with a piece of angle welded to the end of the angle support.