Where do I cut this fender?

[saxart]

I'm going to be starting the repair of this passenger side front fender cup, and I'm curious where to make the cuts on the original fender. Should I keep the replacement part whole and cut the fender to fit it, or should I only cut the rust off the fender, then trim down the patch panel to fit?



After looking at the backside, it looks like the bolt-holes in the patch panel would make a nice place to take measurements from, then transfer those measurements to the original fender.



Any thoughts or experience is appreciated. (Sorry for the blurry pics, I'm not sure how that happened.)