http://devestechnet.com/Home/Deve1950BRestoyou might find something of interest there, and here too..
http://devestechnet.com/Home/MorePixI found that making a cab cart and then having it lower made it easier to work on. Cross brace first, make sure your cart has a pedestal about 8-10 inches high so that when you want to paint under the cab corners, etc. you can get to everything.
Then, when I want to paint the under carriage, I have a few nephews over and they set the cab on the firewall. One of these days I will design a cab cart that allows one person to do that.