Hey Mike,
Looking at your photos where the trunk floor is out. I know we talked about you doing a size for size patch.It's hard to make out fully but It appears you have the drivers side rear of the car supported by a jack stand on the rearend. Make sure you move that before you start cutting the rear rail for the patch,I would move that stand to under the front spring attaching point(torque box) or the rocker panel area.Right now supporting it that way is making that section very load bearing and if you start cutting the rear rail there is a good chance it can twist,buckle,bend,etc. I just wanted to give you a heads up.If you've already thought of this or I'm viewing the photo wrong please disregard.