Anthony, if the rust is localized to a small area, you might want to replace that small area rather than an entire panel. This keeps more original sheetmetal on the car. Also, the process of removing an entire panel, much of which might be intact requires undoing factory applied rust protection, and drilling out original spotwelds. For localized areas, I would cut out the rusted area, and either hand fabricate or use a section of a rust repair panel to repair the area. Also keep in mind that body shops don't usually do this kind of work properly or at all. It will look fine for 6 months until the rust appears again. Their welding, rust prevention and sheetmetal fabrication techniques are usually not adequate. You must hire a very well qualified restoration shop or do the work yourself (if you know how)in order to get good results.
Dimitri