THE ORIGINAL 1960 ISSUED CPO DEVICES
Linked below are three documents from the 1959-1960 time frame that have information about the establishment of the SCPO/MCPO collar devices. The E-8 star sat on the top of the anchor stock which covered the "eye". The E-9 stars sat on the stock on either end. There do exist E-8 collar devices that have the star lower than this and it is believed though E-8 star placement was changed somewhere 75-76 back to this higher location.
Document 1
Document 2
Document 3