Seems like a generous grade. Fields show definite friction and loss of luster so it shouldn't make any MS grade. The large number of contact marks hurt eye appeal and should dictate some net grading even if they don't constitute an official "problem". I would have guessed AU-55 technical grade, with a deduction to 53 or 50 to account for negative eye appeal.
Seems a bit undergraded. Gold is very soft and the coin exhibits a lot of luster. I would have been at MS-62 for this example. IMHO a shoe in for 58 though. Hard to find that kind of luster in any AU gold.