I would guess a lower range AU coin?
Based on the images provided, I would agree with your assessment. My eyes see wear on the high points on each side: obverse - cheek, eyebrow, hair; reverse - sails.
That said, it remains, overall, an attractive coin without noticeable damage (devices, fields or at the rim). I think a grade in the AU 50-53 range is fair.
IMO, you got it at a good price!