Quoting weirdbeard:
Here in AZ, rust is almost impossible to spread.
I plan on going through the rest of the car and de-midwestifying it.
Almost impossible. As I'm sure you know, once something has started rusting, it doesn't stop until the rust is neutralized or removed. There may be very low humidity in AZ, but I assure you it's enough moisture to make the rust in the pictures you posted spread like cancer. It may be at a decelerated rate, but none the less, it's inevitable.
You're doing the best thing possible, which is address the issue sooner than later. But, make sure you do things right in order to avoid having to do them again. For example, you'll need to drill out and extract that rusty hardware the broke off. Otherwise, it will continue to rust, and create another rust hole. I absolutely feel your pain, because I was right where you are when I started my build. I can also attest to the time and effort it takes to fix an issue like this...You've got your work cut out for you. This is definitely no 30 minute fix when done right.
