I've had this 64 sms and always wondered if they ever designated a cameo for it.although it does have alot of carbon spotting it's still very beautiful and eye mesmerizing.
Bc got it from grandfather who had 64 sms set and gave me and my brothers each a coin and I got this one...
According to PCGS population reports SMS can and do get CAM however no 64 have got a CAM yet https://www.pcgs.com/pop/detail/lincoln-cent-modern-1959-date/47 on the link you have to go to the SP tab it doesn’t want to link directly
1964 SMS coins are incredibly rare. They were discovered in the estate of a former mint director in the late 80s. These were purchased by a well known dealer and the coins ended up be authenticated by TPG. There were no 1964SMS sets sold to the public. The mint only made SMS sets in 1965-67 I think your coin may be from a mint set.
Also if the 64 SMS coins have such a small mintage that if any of them were cameo, ALL of them would be cameo, and I have never seen a cameo 64 SMS coin.