[rnstout356]

I am finally getting serious about my '64 SC. I am repairing (rather than restoring) the car. The body is in remarkably good shape. The only serious rust I found was a small area through the left front strut, into the inside of the wheel well and into the pedal area behind the floor board. I have cut out all the serious rust and will need to replace about a 9" square piece of the floor to the left of the pedal assembly, some of the inside of the wheel well and the left front strut. I want to seal and eliminate future rust. I have solid, but surface rusted metal around the areas I have removed so I will have a mix of bright new metal and surface rusted original metal to paint. I want to paint (or otherwise seal) the new metal that will be covered when I install the front strut. I also want to seal the inside of the strut.

I have a couple specific questions:
1) How should I treat the mix of new and old steel? It is hidden, so I am not terribly concerned about how it looks, but I want good rust proofing. Rust encapsulating paint over the rusty parts, but how should I treat the adjacent new steel?

2) How should I treat the repair piece behind the strut and the inside of the "box" of the strut? It will be new steel, but once I weld on the strut, it will be enclosed and hidden. I really want to get it sealed, but am not sure if I should paint the inside then weld the part on or do the welding then try to get paint into the strut.

3) I plan to overlap and plug weld the new metal to the old and would really like to treat the space between the two metals where they overlap.
I plan to add undercoat over the paint on all the exposed parts, but really don't want rust forming in the hidden areas on the new steel.

Thanks in advance for you wisdom.