that highly polished surface amongst the IGWT and Date is very evident. I didn't even see the MM before I figured it was a proof. Oddly the "S" looks like a "5" .. probably took a hit up top.
I also found a 1999 S impaired proof in a roll of quarters. Use to get them almost every day as a toll collector 20 years ago. Sold them all. Now I only have one.