[MOTORHEAD]

OK, an adjustment of approx $500 retail to make the problem go away. (for them, but not for you) Yeah, trying to find someone proficient in alum sheetmetal work is tough! I had to replace most of my front clip using 5 factory pieces and found a few, but thousands of miles away. Ended up fitting them myself, and having a local british race car guy tig it all together. It was not smooth enough to leave bare, so I painted it.
I don't know about the FIA hood, but all 427 panels are .060, not what I would call thin.
One thing you might try is a local metal sculpture artist. Some work with aluminum and weld or "braze" it together. Many years ago in an aircraft maint shop I worked in, a sales guy sold us some "aluminum brazing rod and flux" it works with oxy/acy torch at lower temps, and I was "brazing cracked .032 and up sheetmetal with no warpage. I still have the flux ! I think an alum sculptor may be using someting similar to this.