I did not post a grade review on this (must have missed it) but I think this is AU58 slider.
Having seen a fair number of Bust halves over the years, this is based on the overall appearance of the coin. It is much too nice for a low Mint State grade (below 64) but the luster is not in accord with a MS64 Bust half dollar.
I am going to agree with jacrispies that this is likely an AU58 coin that has just the faintest touch of circulation/handling which has disturbed the luster.
Many things in coin grading are subjective (although the
TPG's would love for you to believe otherwise) and sometimes you just have to go by how a coin "looks" overall.
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