Charleston slave badge from 1852 for Porter No. 505

This is a square metal slave badge set on point with clipped corners. On the recto is text that reads ”CHARLESTON [stamped]” across the top. Under that is “505 [punched] / PORTER [stamped] / 1852 [stamped].” There is a small cut on the top proper right edge. There is a hole punched at the center top.