Inner Fender Repair Panels

Does anybody have any experience with the Sherman inner fender patches?
I'm doing a 67 Dart GT restomod, and the car is surprisingly solid. It was undercoated so explains most of but it's rotten in a few places.

Front fenders shot, and the tops of the inner fenders. Rockers have rust, but the quarters and trunk are solid...

Here's the repair panel....



Thanks..