Awesome medal! Indeed. That show got gory for History and I'm sure the real thing was much worse. I wrote some of the music for a History show on this month called Hunt for the Zodiac Killer. Being a history geek I've always wanted that network credit... sadly didn't come from a lighter historical topic but I'll take it.
I hate to say this, but that is way over graded. On the obverse, the legs are worn flat, when they should be rounded, the head has lost lots of detail, and the breastplate is heavily worn as well. The obverse has lots of wear in the water, all detail is gone in the ship's shields, the dragon's neck shows wear, and the sail has lost its sharp edge along the left. I would grade this a 45 at very best, luster or not. Here's my MS62 Thin for comparison (give it a sec to load) -
I just noticed that my editing removed a couple of chunks from the obverse. Here's another pic of the obverse in the slab, there's nothing missing from the medal -
I'm not convinced that there is wear on the OP's coin. I think it is suffering from poor photos. I know the TPGs mess up, but you're saying it should be 55 or lower, and they gave it 63 in hand. I'm going to trust their in-hand versus the poor pics we're trying to guess from.
I am gonna play with some photos, but the Thin Medal has textures in the fields that this one does not have. I am not saying that PCGS was right, but these two definitely didn't strike up the same way.
Maybe you should have waited for a different coin in a slab? The coin in the pictures still looks AU to me. The legs have a flatness that reminds me of Standing Liberty Quarters. On the latter, the flatness was sometimes caused by strike weakness, so I wonder if that is what is going on here. Seeing the two examples posted above, the legs look to be well-struck, so I do not think I am seeing a strike issue. That is also assuming that the strike was consistent for this issue (which might not be the case). I'd like to see this in hand.