MS-64 It looks similar to the one I have with white surfaces. The toning hides the small marks, which is why one must be careful in grading toned coins.
That is one sweet Hudson. Couple hits on obverse. Usually weak strike, especially on obverse but yours looks better than normal. MS 66 with that toning 66+ money
To repeat myself, from another GTG commemorative, "Most commemoratives grade MS due to never being in circulation and unless they are MS66 or higher, they seldom demand a high price." Most are MS65, as is this one, I expect, although I don't care for the toning at all.
Didn't get a chance to guess grade, but wanted to comment how lovely the reverse looks. The colors around the ship are fantastic - can't imagine how awesome it must look in hand!
Well, before the grade was revealed, I was going 66 because I didn't see any marks on the large planar areas of the obverse or the sails on the reverse. That amount of green on a coin always raises concerns and good to know it's toning and not the dreaded green slime! Probably the nicest looking Hudson I've seen.