ThanksNot quite the same but this post might give you a few pointers on making a repair piece for your battery tray.
This was 1.2 thick if I remember and was fairly easy to work with.
https://www.mig-welding.co.uk/forum...-from-the-brink-hopefully.81348/#post-1160068
If you can make forms out of wood, or better still steel if your working with thicker sheet, you can make all sorts of shapes.
I've ground shapes into plate or welded bits of scrap together to make forms.
Steel is brilliant for the job, if you take too much off it's easy to put it back.
With a decent form all you need is a hammer, some G clamps and a couple of blunt chisels to make that.
I did this repair before I had much in the way of body work tools, or practice.
Reminder of some good tips.