Hi Jim. The coin inlay with concentric circles looks like the fine lines on a phonograph record. The "smooth" coin inlay is smooth, shiny and has no concentric circles. See TCR-8, P.360, Castaways, for a scan. The difference may not mean as much as we once thought. An official chip manufacturer told me that all of the coin inlays have the circles when made. The ones with smooth shiny surfaces were left in the polish tumbler longer which removed the circles. There was never an intention to make them smooth & shiny.