gdrill is right in that taking the time to do a GOOD job on a patch will probably take about the same amount of time as replacing the entire inner fender. However, I believe that if the rest of the metal is, as you said, VGC, I would patch it to retain as much original metal as possible. I'd buy two new AMD inner panels and cut out what I needed (unless the area could be done with flat steel with a bend. couldn't tell from the pic). Getting EXACT cuts so as to leave the perfect gap for the perfect butt weld is very time consuming. If you can do that, go for it. It may be a bit easier to replace the entire panel, but you'll be cutting a LOT of spot welds. Good luck however you do it. If you lived close to me, I'd be glad to help.
