Reinstalling Hornet dash

Last night I was going to reinstall my newly painted dash into my 71 Hornet.  My memory fails me how it attaches to the body.  Obviously there are a series or chrome interior screws that secure it to the ledge below the windshield.  There also is apparently supposed to be a bolt on each end that screws into the inside panel of the body in front of the door opening.  However, when I look at that panel on my car, I see no place for a bolt to be attached.  There is a rectangular knockout hole in the area where the bolt should go.  What is supposed to be inserted there for the bolt to screw into?  I have looked though all the parts I have an see nothing that would make me think it would work there.

BrotherBamc wrote: You're missing a "caged" nut.

Last pic is a little blurry, but I hope you can get the idea.
I've had to search for one on my passenger side. It's a rather unique cage nut. I thought if I couldn't find an original one you might be able to spot weld one in.

and for what it's worth, it's 5/16....