I painted my 59 all in parts while dissassembled. It made it much easier as you don't have to worry about dry lines and overspray from painting one panel at a time. Plus putting everything on saw horses and painting it flat makes it much less likely to get a run or a sag. I painted the interior first and then flipped them over as the exterior coat was what matter the most. Assembly went fine, just take your time and be careful. You can even use rags on the edges and have everything loose, then pull the rags and tighten it all up.
I probably won't dissassemble my 72 to paint it, maybe, but I already have the bed slid back so I can do some cab repairs.
