I have a 55 door on my 56 and put the trim on as Lon suggested.Took measurements from the other door.I drilled the holes a little oversize to allow a little adjustment capability.Lon,you're correct,55 and 56 doors have different latches,but they will interchange.There are some other very slight differences in the doors,but they don't prevent swapping them,and are unnoticable on the car.