65 Riv rear bumper question

[Rufcar]

In a few weeks I will be disassembling my Riviera for painting and the rear bumper will be

re-chromed. That said the question is this. How flat across the bottom is the rear bumper?

To be clear if your looking at the rear bumper at say eye level and you held a straight edge across the bottom edge how level or flat is it? I notice mine has a slight indentation along the middle with the license plate area being raised up the most. Is this common of is it flat across from left to right?

Tkx Jim F