Best to keep it open and flat, as I have learned. Hopefully your install goes easier then mine. I had to get two tops from two different vendors since the cut was not correct. Which is why he wanted to just make his own. Not sure if my top frame was off or the cut is that far off.
One thing for sure, I am glad I did not tackle this job myself. I think I would have lost my mind trying to install, given the challenges he had, even with his decades of experience.
Dont forget new top tension cables. If you cant find them, I can dig up the place I got mine from. They were listed only for a 67 on the site at the time, but they may have resolved by now.