Hi Boobee
I didn't use a metal shrinker for the curve as that would crown the door. I made special dies for my bead roller to start the process and finished the fold with a hammer and dolly. No heat used either. After the folds were made we used spot welding to hold in place. Barry hasn't found a suitable replacement for the thimble but is working on a local heavy industry making them at their expense, then they would truly be OEM.
Regaerds
another Bob