Frustrated with inability to do body work!

I had a concave body line on my 57 Ford fender the same place, like this:
View attachment 1715083217
I never could get it "right" so I did my best and primed it. It turned out to be about a 5 footer, but that better than a 10.
I still hated those "last minute" headlights. They were supposed to be quads for 57 but the quad headlight law didn't change in time.

Yea, that one would be a PIA for sure.
I seem to be ok with compound angles like the scoop but have problems with big flatter places, and I really do think it's an impatient thing.
What's up with that?:D
This is my (antenna and badging delete) fender and it turned out okusing the round sanding (I aslo used pipe insulation with a dowel inside it) and worked a large length of area lightly until I was sanding with pretty much the entire length of the 12 inch round sanding roll using an X motion even though I was really only getting rid of the antenna hole at this end of the fender.