Ideas on Rear Quarter Replacement

Thanks for the tips guys! I won't cut anything til I have the new sheetmetal. It's a partial rear quarter. The trunk extension isn't too affected, I could probably save it and cut forward of that body line. My main concern is the area in blue. Trying to line that up perfectly with the new metal is going to be difficult. Is cutting vertical in that area a common practice? I prefer not to cut and replace the entire body line just above the gas cap from the drivers door jam to the trunk extension just to fix the lower rear quarter. But I'd hate to screw up the wheel well.