Welding is almost done on the tailgate. Lots and lots of welding. I did discover I suffered some heat distortion even with me clamping. This happened along the top edge where the cutout is. Both sides bent in towards the box slightly. Hopefully the 10lbs sledge hammer will help them back to where they should be. Overall I am pretty happy with how this has turned out.
The next thing will be making new sides for the box. These should be a lot easier in comparison then the tailgate. Fingers crossed.