Shocker

5 weeks later, and the rear springs are still not here from Dallas Mustang. 

I spoke with a POR15 rep today.  This is not going to be easy, but here's the outline of how this is going to get done:

1. Interior floor pans and front fender aprons will be thoroughly washed down with aircraft stripper.  This should remove any traces of paint.  
2.  The aircraft stripper residue will be removed with many sponges and very hot water.
3. What isn't removed will be sanded off.
4. All areas of the car receiving rust-preventative paint will get a thorough washing of Marine Clean, to remove any grit, grime, oil, etc.
5. Many more hours will be spent with a sponge and HOT water, washing off the Marine Clean.
6. The Metal Ready* will be sprayed on the car to remove rust, etch the metal, and prepare for the POR15 paint.
7. Once again, hours of wiping off the above with a sponge and hot water.
8. Before the next step, I will apply some thick tape on the underside of the car, where pinholes exist.  
1. The best solution would be to remove the pans and weld in new ones.  Unfortunately I do not have the experience to do this, nor do I have the tools.  I could learn/pay someone, but I feel that the very minimal improvement made by putting in new pans would not offset the cost.  The pans have been given several "tests" and they are very solid.
9. Now that the metal is ready (get the pun?) the POR15 Rust Preventative Paint will be applied with foam brushes.  The paint is self-leveling, so foam brushes should work fine.
10. After one coat of POR15, I will put down a layer of POR15 Power Mesh on the floor pans with pinholes.  This is a reinforcing fiberglass type material that will provide a little extra stiffness, and will seal the pinholes from the underside.
11. 2 more coats of POR15 will be applied.
12. Tape will be removed from the underside.

*Metal Ready has apparently been renamed to "Prep & Ready"