It has a straight grade. I cant tell if its a mark or a strike thru. It doesn't go into the banner or the wing, so I can't figure it out...
Call me whacked folks, but I think I see a much higher grade coin here . . . MS64 or better. That long mark left of the eagle looks as-struck to me. No matter how it grades, it's a beautiful coin C-B-D.
The photo makes it look like wear is present. If the coin is actually mint state with no wear, you are right, it could easily be MS64. I chose MS61 as a net grade for the presence of wear on a coin that presents as an AU64.