Len - the only way you'll fix that will be to bend the door - not easy, but possible ... I did it with a door on daBus where I had to scratch build the bottom foot or so and didn't get it quite right .... didn't have the finish paint on yet tho'

when these trucks were built they could pick and choose doors that suited the variations in shape of the cab and fenders, and the original fit wasn't always great [especially around the dogleg], they weren't building show trucks
Bill