I am going to get my bumpers re-chromed. The rear has some minor crash damage. The chromer will repair this for me. The biggest problem it creates is the it has distorted the radius. By pushing the bumper in slightly it flattened the curve and the passenger side (left as you look at the rear) end of the bumper pulled away from the car.
I will make a cardboard template showing the radius using the mounting points. It would be a good check though to have the measurements from one end of the bumper across opening to the other. (The pic below is not where the measurement I am thinking. It was just for scale).
I know the bumpers were ‘fitted’ and that measurement won’t be the same on all cars… but if any of you have that measurement it would be a useful point of reference.