
The 1821 Numismatic Forgery has been around for a decade or two and it is a centrifugal casting that included the edge. The copies I own have three edge seam lines (one is visible on your coin.)
Personally I think the forgers (Chinese) were trying to make the Lions look too much like Dragons.
One major error they made in this case is that they used a colonial edge instead of one of the mainland diagonal designs.