Gerahead's 71 Dart

That actually doesn't look too bad. I have seen and replaced much worse such as that on my personal restoration project. May I suggest that you finish stripping all filler and primer from your lower quarters and excise the worst visible rust area leaving 1/8" sheet metal around all formed edges so that you may do a more comprehensive examination of backing metal before you purchase your replacement panels. If the visible exterior looks the way it does, chances are you may or may not get lucky with the inner quarter panel steel. This is assuming you have not completed this typr of work before and if so, please disregard the afformentioned :-). Keep in touch with any questions if necessary. I have been doing paint and body for a while and am willing to assist if need be.