A bit of hammering with the right shaped hammer to fix it. Much better.
About as good as I can get it right now. A bit of CAD work to get a template for the lower grille reinforcement panel.
I put a step around the edge so it sits flush with the grille flange underneath and sits down from the top. Having the main part lower means I could put a drain in the panel that didn't need to go through the grille flange as well. Even though I stretched the bead area first on the English Wheel, it is still bowing down in the middle. This tells me the top of the bead needs more stretch to level it.
So I made up this T bar from some rusty bar that fitted the bead. Hammered down into the hollow of the bead directly over the table. Lots of little hits working back and forth and it straightened right up. Might work well as a post bead stretch even if you have not wheeled it first. Certainly will improve it. I had also rounded the ends of the beads as usual with some pipe with half of it notched out of the end.
I was worried the beads were a little bold but they match the ones in the doors and went with that. Once behind the grille they don't look too bad. This can now be spot welded in place. Will just add some sealer over the gal coat beforehand around the edges to keep water out.