Here are some pictures of the door braces I built for my ragtop.

I based my design on the one's Clark Classics has in their pictures of vert's on a rotissorie. The brace is made from some scrap angle, a piece of channel, and 1' square tubing. I started with the car on tires and door gaps good. The upper rear anchor bolts up using the folding top mechanism bolt holes. The bottom rear bolts to the seat belt anchor. The front is thru bolted. The doors can stay in place with this method.