All the screws in the bottom rear wall are missing or stripped

[Country Campers]

Brian -- really appreciate this. I am thinking to remove all the floor screws on the trim and only leaving the wall screws of the trim connected. This way the trim will float on the floor, hard attached to the wall. Thoughts?

That might be worth a shot. A few screws to hold in place would be all that is needed. I have reinstalled screws on mine different times but have not checked lately to see what is going on.

Brian