Well I hope someone says what it is. I found one with similar attributes and it may have been around the same year. I put in my keeper bucket for now. Hope it"s something nice. Good luck!
2007 was one of the years for the Satin Mint Sets. I noticed similar anomalies in the fields of hundreds of circulation-strike SQ's from 2005-2008. This is just a theory, but I came to the conclusion that many of the satin finish dies deteriorated faster than the Mint anticipated, and since they felt these dies still had some useful life, they polished them up a bit and used them to strike circulation-quality coins. Chris
