Floor Pan Opinions?

1964 Valiant Convertible

I've owned this car for all of 2 months. I pulled the front seat to crawl under the dash. When I stepped in, the floor pan flexed inward, and when I stepped off it sprung back. SO, now concerned with the integrity of the pans, I pulled the seats and carpet. The following is what I found:

The view from the driver's side. The pans have clearly been given some previous attention. Notice the sheet metal that has been riveted into the floor of the back seat footwell area. This sheet metal seems excessively thin, and this patch job of poor quality
View attachment IMAG0178.jpg

The floor pan again View from passenger side, the front areas look okay, I guess?
View attachment IMAG0182.jpg

A Closeup of the patch Thoughts?
View attachment IMAG0180.jpg

I know next to nothing about body work and would like to hear some input on this. I will be taking the car to a body shop in the near future, hopefully to get media blasted, patched, and painted.

(I have no idea why these other 2 pics attached)