Images courtesy of Heritage Numismatic Auctions

Significant examples:
NGC MS-64 (illustrated above).  Overton 104.  Ex - Superior Galleries' "Pre-Long Beach" Sale, October 1-3, 2000, Lot 3270, where it was described as follows: "Small lumps near milling at stars 2 and 3. NGC MS64. Deep, beautiful "old silver" toning on both sides, the result, we are sure, of close to 200 years careful storage away from damaging elements. There are no spots or tarnish streaks; instead, the coin dazzles the eye with its soft luster and incredible smoothness. Smoothness that is unblemished by obvious marks; certainly no hairlines. Minor weakness in the strike is inevitable on this variety, where Liberty's breast falls opposite the clouds and stars on reverse. The two high points lying opposite one another were a minor design flaw, causing weakness here on most dates from 1801 to 1807. Only rarely does one find a full-fledged Mint condition Overton-104 offered. In fact, the Overton reference book lists the Condition Census topping out at '55' -- About Uncirculated!"

Sources and/or recommended reading:
"Early Half Dollar Die Varieties 1794-1836", Third Edition, by Al C. Overton and Don Parsley