PCGS missed several grades for me with almost all of my morgans so that doesn't surprise me. the 79(O) is known for average to above average strikes. the slight weakness around the ear and just a slight weakness in the breast would put this one in that range. I'm not sure how much the
TPG's put weight on whats average for that particular year though. luster is broken all over both sides. you have a good hit near the wing and a couple black marks on the reverse that probably could not be removed. the wear to me puts in the AU58 bucket but the amount of wear on the profile itself, especially the chin area which is a key area, most likely is what resulted in knocking it down a peg.