Way kool, I have a '49 Caddy 4dr I have been wanting to do something like this to and this gives me more encouragement.
I didn't see the new pic in rolls'n'pleats But thats way cool! And yea I am really glad to see it got done right. As for the structural stuff I didn't change the frame any,but the door jambs got some nice big steel supports welded in...1/8 steel plate that was 6x12 folded so it formed a right angle. My doors were coupe doors(about 6 or 8 inches longer than sedan doors)... but it took a ton of work to get it all close...next time I would just lengthen the stock doors and modify them so they mimic coupe doors.