Back of cab pinch rust pics included

[T97]

What are you guys doing to match the curve of the pinch along the floorboard on the back of the cab? I dont see any reproductions of these body lines other than on the cab corners and i dont want to have to buy 2 sets of cab corners to cut up to match.

I figured after i cut out and replace the bad metal i would treat both surfaces and seal up the the gap behind the gas tank with seal sealer for the future.