Great write up.
I had a few bolts twist off or strip out over time. My solution was to drill and tap some 1" wide, 1/2" thick flat bar about 2" long. I got rid of the nut in the frame with a 1" hole saw. I then drilled two 1/2" holes about a 1/2" to either side of the nut hole. I fished the flat bar down in to the frame from one of the many factory holes. Once I got the flat bar into place, I welded around the hole and the two plug welds. Ground it all smooth and painted.
By the way, a wire snake works great for this!
Beat it to fit, paint it to match!
Wheel, Wrench, Repeat.