The 1806 O-127a Half Dollar is a very rare variety, with only 18-20 examples known. In 2013, a new, potentially finest known example appeared on the market. “This specimen was unattributed when puchased by Vic Bozarth of Boazrth Numismatics, Inc. of Brenham, Texas. Vic Bozarth sent this coin to JRCS member Mike Clark who had the enjoyable task of attributing and discovering a new specimen of this very rare die marriage.” According to Steve Hermann, “The new PCGS VF25 specimen may be the finest known example or tied for the finest known with the VF25 specimen listed in the recent JRCS PTHD census.”
W. David Perkins, “New Specimen of the Very Rare 1806 O-127a Half Dollar Discovered,” John Reich Journal 23, no. 1 (April 2013), 40.