Body Identification of random body fasteners.

[Tim_Coble]

In the photo below, I have five square nuts welded to the bottom of my tub. The through hole (near the wire harness) has 3 locations, one on each side and one in the middle. They are too far back for the rear seat attachment, any ideas what they might be for? Next, what's the blind hole that is above and to the right of the body mount? It is mirrored on the other side. The threads are gone so I need to know if they need replacement.

Thanks.