I do, but not this coin. This was purchased with Sticker from member Tom B on his site: http://www.tbnumismatics.com/
On the birds chest on the reverse, there is a tiny "S" engraved. Legend has it the mint employee was a Superman fan and made the engraving. About 1/5th of all of the proof quarters from from that from that year from that year have it, but a lot of people don't know it exists.
Wishful thinking on the 67-68 is fairly baggy but otherwise clean and problem free I'm saying ms 62-63