Since I will be putting the seat back in next week, I decided to remove the old carpet (not keeping it) and get an idea of the condition of the cab floor. Since this is the worse area for rust on these trucks. I removed the metal sill covers that where very rusty and discarded. In fact 4 of the 8 screw holes for the screws that hold the plate on are so rusted the screw just came out. But, all that is going to be replaced anyway.
Back to the carpet and floor. Got the carpet out and……..well……the floor is good and bad. I guess I should say where its good its good….and where its bad its bad. About 75 percent of the floor is in good shape…..not much rust. Cab corners (common) and the front foot wells are rusted…you can put your finger through areas of rust. Also, behind the seat area is just a small area its rusted at the seam and you can see though it…..lol. Might be able to just repair it with a rear cab corner panel.
Here is what I found…….

Sill Plates
As you can see…pretty rusted. They are gone.

This is the passenger side and its actually not too bad. You can see the fiberglass patch someone has done in the past, its in the middle towards the dash. I may just have to replace the rusted area on this side and that will be good, but I have to investigate up under the dash and see what shape its in. A lot of times the windshield leaks at the bottom in these truck and no one knows, so it rusts up under the dash. Does not seem that this has happened here due to the middle front of the cab floor is good. But………..

Drivers side…..worse than the passengers side. You can see the hole punched though up in the left corner…and also in the right corner. This whole panel will probably have to be replaced. Someone did a lot of patchwork on this side years ago. See all the age cracks.

But, the whole floor is not all bad, the middle and under the seat are good. I tapped on the floor in several places and it sounds solid. Of course I will evaluate if its better to repalce the whole floor or just sections is a better option. The body man I have wants to just replace what is damaged.
Seat goes back in next week so at least I can drive it..if need be. I will be working on the transmission linkage next so stay tuned.
Seat Brackets (set back)
Seat brackets have been welded, sanblasted and painted. But, I am still missing some parts. There is a couple of springs I need, these make the seat adjustment handle spring back and enable the seat to lock in the position you want. I was a little cramped when I drove it home, and I think I know why. Since both seat brackets were broken it was forward a little bit and I could not move it back. I hope that when I get the seat back in (with all its parts) I will be able to move it to the far rear position and I will be more comfortable. Here are some pics, the seat will get re-done at a later date with new foam and leather coverings.

Drivers side ready for some grease in the slider.

Passenger side. See the small slot on the right….this is were the locking bar and spring ( I dont have) go. I am still looking for the correct spring.

This is the locking bar. This spring I bought at Ace Hardware but it will not work. Its too small in diameter. But, I tried. When I get it all together I will take some pic and update everyone.
Here are some pics of how I might redo the seat.

This seat was the top of the seat with the plaid design. I might do this, not this color. But the plaid could look cool.

Here is another one. I like this one too. Might even do colors like this. This seat is in a older truck than mine, but the seat is about the same.
Looks good and sounds like you have some good ideas of how to repair the rusted spots and age cracks. The seat ideas are great.
Well…..I dont have the tools to replace the floor….but the guy at the school will be replacing the floor. He only wants to replace what is bad, keep as much of it original as possible. But once the media blasting gets done we will see what exactly is damaged by rust. But, it will all be gone.