Tony,
I put inner and outer repair panels on both doors of my '66. The whole bottoms of my doors were rotted out.

I got my panels from LMC Truck. They were good quality heavy guage metal but did not have as good a fit as I would have liked. I decided to rivet my panels in since I do not have a MIG. Most of the bends where not as sharp as they needed to be and the inner panel fit best by laying on top of the existing metal. I now have a "lip" on the lower part of my door but I intend to put carpeted door panels on that will hide them. The outer panel fit better and I crimped the lower edge and sides over the top of the inner panel like the doors were originally made. You can tell the outer panel has been put on but on this truck it doesn't matter. The arc or curve of the panel was not the same as the door.

I sanded, triple etched and painted the insides of my doors since I had all the guts out. I also sprayed undercoating in them. I was only able to do this since i was riveting my patches on. If you do buy the inner patch panel be sure to do the following:

1. Clean all the oil off of the panels. Cut them down to only what you need. They come with twice as much as most repairs require.
2. Etch, paint and "undercoat" it before assembly if you don't weld it on.
3. The panels do not come with drain holes cut in them. Be sure to cut two in at the bottom.
4. You will need to pry open the bottom and side seams of your outer panels. Clean all the rust out and prep the metal. Put a sealer(caulk) in the edge joints before you hammer them shut.
5. I did not spot weld the edge joints in case I need to replace either panel again.

That's my experience. Use what you can and ignore the rest.

BigMac