Seat belt hole on new floor board

Hello FABO!
At some point this car got a new floor i think. (I think.) There is a hole for where i assume (i assume) the outside seat belt bolts. Do I assume (dangerous) that there is a factory nut in the body on the other side? Is the factory nut on this 67 barracuda fastback part of the inner rocker? or do i put one in?

Thanks FABO!