Recently purchased an MS-66 of this coin and immediately noticed some luster impairment when it arrived... looks like someone used acetone/q-tip to clean spots, or maybe oily finger rub marks. Because the marks were in the center of coin near the error leaf I wasn't too happy. The main spot is above and to the left of the error leaf, adjacent to the large normal leaf. There is another, lighter spot to the left of that one, near the cow eye. But the attached photo is from PCGS! http://www.pcgscoinfacts.com/Coin/Detail/814033?redir=t So of course it turns out that all the low leafs have these luster anomalies, which is probably common knowledge to some here, but I couldn't find anything online about this. Perhaps the mint worker who tooled with the die got his dirty little fingers all over it BTW I love these genetically modified clad corn mutations!
this is called struck thru grease areas . it is extremely common on our newer coins. actually what it is that gets on the dies is a mixture of all kinds of stuff like metal dust and grease.
