Audrey's 1965 Barracuda project

I'm just an amateur on this fender patching stuff, learning as I go, I need to make the edge just a little bit rounder on top (top of the picture that is, side of the car), so it fits the chrome light ring perfect. I had it rounded good before I welded it in, but in the process it flattened out a bit. The lip (that's gonna hold the pot for the light) will hold back if I try to stretch the metal on the side of the panel, should I make a cut in it, stretch the side part so it becomes rounder and weld up the cut?
I need an experienced persons input on this...

Screenshot 2021-05-02 at 00.56.47.png