IN My opinionI have seen this coin looking better, I seriously believe the coin, in this condition grades better than AU, I see plenty of original luster, I see a crisp strike, where it is clearly able to be seen.
I do not know what your intentions are for the coin, I collect commemoratives and I DO NOT have this sweet coin in my collection, IF I read this correctly you spent $75.00 dollars, IMO, You did well, sure the coin has some "hard on the eyes issues", past that, you have a nicely struck, lusterous coin with good bones.
I would NOT clean the coin in any way, I see how people could easily say the coin has a "hard on the eyes" look, but they are not looking past the surface, IMO.
I collect commemoratives and this coin is NOT as bad as it on first look, appears, just my opinion, collecting since 1963, goodluck, Mike.....