Engine compartment repairs

I got a bit scared yesterday removing the battery box when I reached the torsion bar areas. The battery box sides are sandwiched between the torsion bar mounting pieces and the gas tank floor area. I think I can't effectively make use of the whole battery box side replacement panel. I'll have to cut off the backs of them and butt weld them to the front of the torsion bar areas. Unless someone has been there before and has some tips? I'd like to do this right, but I don't want to wreck more metal than I need to trying to peel spot welds.

So, today, I moved to the engine compartment. Lots of holes back there, easier to get to. I needed to go get a big sheet of 20 gauge sheet metal to fabricate my own patches. I found a roofing/metal fabrication company in downtown Durham that sold me a big sheet that they cut on a medieval-looking press the size of a bus.

Most of the day was shot, and I only had time to do one patch. But it was a pretty large one in a somewhat tricky place, so I'm happy. Here's a before and after:

More pictures here.