Tailgate cable nut disappeared inside the tailgate

[rszimm]

My 2002 2500HD had the cable fall off.  When I went to investigate, the nut inside the tailgate must have fallen out.  I'm guessing it's still inside the tailgate, but the tailgate is a welded together assembly.  Even if I had the nut out, how would one go about getting it back into the hole that it's supposed to go in?  Once I get it there I can probably put a few tack welds in to hold it there for the duration, but getting it there is a problem for sure...

[rszimm]

So if you take the latch off that side there's a nice hole to access the back where the nut should be.  I pulled that latch but couldn't find the nut in the tailgate, so I found an M8 nut in the shop, welded  it to a fender washer and tack welded that to the opening so it wouldn't spin while torqueing the bolt.  Worked great!

 

So now it seems that the 3000 lbs of fiber cement I put on the tailgate while I had that cable disconnected has caused the pivots to bend a bit and the tailgate seems to be slightly racked.  Any suggestions for techniques for squaring up and aligning a tailgate?