Hope you don't mind me adding this but my father showed me a way to make up panels like this with a curved edge from a single piece of steel. First you have to cut the curve onto two pieces of thickish chipboard to act as a former.
Sandwich a piece of steel between them leaving a slightly larger than flange size sticking out and clamp the two pieces together.
All you do then is carefully tap the edge over in the same way as you start off a door skin. As long as the flange isn't too wide you can do some quite complicated shapes.
If that doesn't make a lot of sense I will do a drawing to explain.
Really impressed with what you have been doing, I think it will probably end up better than it was when new !