I just completed a major bare metal project on my early 71. I've read Pantera steel was of the same genre as Alfas, Fiats, etc. of that era acquired from Russia in war-related trades. That rings true to me, as my rust was significant despite having largely been garaged. I've seen far more sound U.S. and British cars that have sat out for years uncovered.
That said, the biggest problem areas tend to be the forward portions of rear inner fender/wheelhouses, especially forward of and above the fuel tank, same on other side (remove side engine screens to observe but still hard to get a good look), bottom portions of door latch pillars (remove guides to observe), throughout rockers, potentially frame rails and connecting structure, door frames and lower outer skins, "dogleg" panels fore and aft of doors toward bottom, radiator support, and floorpans. Some also have had rust in roof and around windshield and in most any sheet metal spot. Mike Dailey's
www.panteraplace.com has some diagrams with highlighted spots. It's hard to get a good inspection of an assembled car, due to the goopy undercoating, the panels that obscure some of the worst areas, and bondo from half-ass previous bodywork. Remember, it's a monocoque, so a lot of those can be structural areas. Good luck (still well worth the trouble).
