These are the two mounting systems that were combined.
I tack-welded the two together to hold them steady while welding. Note the differences in thickness of the two materials. This was a challenge, becasue the heat can burn away the thinner material without fully bonding to the thicker material if you don't perfect the technique. Considering this is my first official weld to be used for on the Jeep, it was a challenge! (I had ran some practice beads on scrap metal for 5 or 10 minutes prior to this as my truly 'first welds' . . .)
My first weld! I went a bit slow at first, causing some extra material to build up, but it was almost perfect through the middle, and then I went a bit fast at the end, causing some gaps. I truly spanned the gamut of possibilities.
I ground down the bead on the back to make a flush mounting surface - looks like pretty decent penetration, as it appears to be a single piece of metal.
I had to further enlarge the slots in the frame to insert the new, longer angle brackets. I blasted the bare metal which was exposed with a bit of primer, and called it a day!