For sure I have no experience, but I couldn't imagine how you could do an entire car without disassembling - especially a restoration, even if its only a partial. That media would be in every crack and crevice just waiting to spoil a fresh and shiny paint job no matter how well you cleaned. If he just wants to remove the lousy brush job, a pack of 80 or so paper and a block will do it. A DA is better yet. The positive with a body off is also giving the restorer a chance to replace frame welting and wood mounts. It sure makes other maintenance easier as well