That's not an easy one. I guess AU58.....there is light wear. But MS62 wouldn't surprise me either. It's a Slider. Nice coin.
If the grading company's are holding true this is definitely a slider. I wouldn't be surprised to see it in a 63 holder.
AU55 I'm grouchy today. Seriously, grading peace dollars in this range frustrates me. I've seen them where some folks claimed they had rub and I flat couldn't see it. I can see it on this one, so I say no way MS.
The nicks don't disqualify it from MS and it has strong luster. No matter what they graded it, this coin was circulated lightly. AU 59.5
For a Peace Dollar, I think that's a very nice coin. I know everyone else is guessing lower, but I'd think MS65.