Where do these gaskets go?

Im not familiar with a 66 but there are gaskets just like that on a 72 dart rear bumper bracket. They go between the bracket and the body.
Thank you. That's what I was figuring. Just seems weird to me that they'd use a gasket at a point where it doesn't really matter if water gets past that surface.

On a '72, do those mounting points go through to the trunk interior? I don't believe so, but I'm not 100% sure. Thanks again.