Considering the locations of the reverse die cracks, in this late state, die collapse could be causing the weakness at the O and the 59.
The cracks at leaf 14 and 16 are aimed right at the O of ONE. You can see an interior crack along the top of the O also. You've also got cracks at leaves 5, 7 and 10 and another interior crack through the N of ONE going down through the NT of CENT. All of those cracks could result in die collapse to leave parts of the lettering in those areas weak. It's not uncommon to see this in late state coins. You might even see a bulge in the fields in around those areas which may not show up in the photos.
Nice coin! I love these late die states.
Here's an example of another coin with late state die collapse showing weakness and bulge in the fields.
