I enoy watching a MotorTrend program ( NO I don't stream) that shows guys fabing those curves and compound curves, but they have all the tools, English wheel, etc and they know how to use them, I would not have a clue. There is a simple thing called a sandbag which is a leather bag full of sand , and it is useful to pound in a curve. I ave used them yars ago making bit and spur parts (trim).
I understand what you are saying. I fabed the metal around the wheel openings for a 64 and 5 Dart, and 62 Lancer < one side, I bought a piece off a bone car for the other side!!!!! \
I watched an English guy on TV yesterday, building an aluminum body make a compound curve heat it with a rose bud looking deal and bend it like you would not believe.