The 1806/4 Quarter Eagle is a very rare date, with less than 100 examples known. Most of the certified examples are found in either higher circulated grades or lower Uncirculated grades (meaning MS61 to MS63). The very best example is a single PCGS MS64. Even David Akers, who claimed never to have seen a legitimate Mint State 1806/4 Quarter Eagle would have loved this coin.
At least two of the known examples have a distinct cud at the top of the obverse (one of them is illustrated above). The cud may account for the rarity of this date, since the dies would have been retired early or they would have fractured soon after the cud developed.