A beauty. I want to say clean as MS67, but maybe AU58. I am seeing some lack of luster on the cheek and hairline. I hope I am wrong!
This looks like more than flatness / weak strike to me. Keep in mind, I'm an amateur and respected members here on CT say Washington Quarters are a very hard series to grade in MS. Here are the areas:
Thank you for clarifying what you meant. On at least one of the spots, I see a very slight change in color that looks more like toning to me. When distinguishing between toning, striking issues, and wear/rub, the first two will have full original luster that is unimpaired while the latter will have its luster affected. I don't think the luster has been affected and what you are seeing might be a combination of the toning and very slight striking issues. Assuming that I am correct on the cause, it would not prevent the coin from a high mint state grade. Having owned several early Washington Quarters in MS66-MS67, the coin compares favorably and I see no reason that the coin should not obtain full gem/superb gem status.