It was time to weld the stiffener plate in before the bottom gets closed up.
Fast forward - I painted the panel and the body so the panels wont be bare steel on bare steel anymore. Sure its gonna burn a bit when its welded but its better than rusting through again.
I pre-drilled holes in the stiffener so it can be spot welded to the floor later just like the original panel.
All tig welded and this was the biggest pain in ass ever. Basically the way you see it in the above picture was the only access I had getting inside. But its in, its solid and its smooth.
The floor panel is up next!