Here's another place where I didn't want a perfect resto, but something better. I really studied bedliner material. That's right. Like Rhino-Liner. They take tints very well. They don't scuff up either. So, we got some of that, blended it a bit smoother than normal, got it to exactly match the color, and then applied it. Before doing this, as you see in pics, we totally perfected the underside of the car, then rustproofed it all. This stuff is a sealer and really seems to be a perfect solution. I am planning on putting a lift in my garage, and think that this is a good choice for the undertray because it will be so easy to clean to look as sharp as it does now.
The floorpans (on the inside) are a similar substance called Lizard Skin. We tinted it too. It's a really good sound deadener and insulator. I love it.