A lot, yes. Let's start with this: you don't have a '64 SMS. They are exceedingly rare. The odds are incredibly low. You haven't shown a photo or told me where you got it, so nothing suggests to me that you have one. If you did, the indicators are so subtle that I, as an expert, would not claim to even be able to tell, so I'm sure you're mistaken. If you want to be stubborn and pursue this you could get them certified, which would put an end to it. Because the grading company probably wouldn't even pick up on it if it was real, unless they had some reason to suspect you have an SMS, and it's a blind process, so even if you told them, they would likely ignore it. I wish I could be more encouraging but with coins, not adage is truer than, "if it sound too good to be true, it probably is." Now, I could give you the opportunity to check by submitting them on your behalf to PCGS or NGC, but first I have to see them and be convinced myself, because I feel it is unethical for me to take someone's money to grade coins if the odds are they misinformed about what they have by virtue of their inexperience. If I haven't talked you out of it, send me some good resolution photos, I'd like nothing more than for them to be real, and will take a serious look! Marc