Len and Dave- I suspect the door did spring a little when it was cut out- we had to use the torch instead of the saw to cut the door because the tank is 3/8" thick. So it got a little warm. We do have some toggle clamps on the bottom corners of the door, but still have at least an 1/8' gap between the tank and the flat steel flange on the ouside of the door when closed/ clamped down. The largest gap is pretty even across the bottom and extends about half way up tthe door on each side. I doubt we can bend the door back into perfect shape due to having it mounted and the flat on. Could be due to the hinge too- we used tube and a piece of round bar across the top of the door and made a piano type hinge.
I'll get some pictures - smoking a few turkeys Wednesday for Thanks giving.