Charleston slave badge from 1804 for Porter No. 67

This is a round metal slave badge. On the recto is text that reads ”CHARLESTON [stamped]” across the top. Under that is “No. [stamped] 67 [punched] / PORTER [stamped] / 1804 [engraved].” On the verso is a stamped cartouche at the bottom center with the maker's name “C PRINCE.” There is a hole punched at the center top. There is a small piece of metal missing from the proper left side, and a small hole in the ‘6’ of ’67.’