Below are some areas where I have cleaned and restored (under hood, fenders and battery box) on Miss April. I used the same techniques as outlined in the article.
Here is how it looked when I bought the car.....
I will undertake the bottom side of the floor in the future. Good news is they are solid! Here are some photos of the top side of the floors- after some cleaning I did. Nice and solid!! The brown color on the vertical walls (inner longitudinals) next to the floor is glue, not rust. It is the left over glue from the carpeting.
I was able to restore and reuse the original "horsehair" underlayment on the floors. I wrote about it in the Restoration- Blog section. Here is a link so you can see what I did.