Unknown Coin Or Token Struck On US 2 Cent Piece?

Here I've come across a circulated 1864 US 2-cent piece with an unidentified overstrike. On the 2-cent's obverse is the number 20 encircled in a wreath that looks very much like one that would appear on a US coin; the reverse shows another 20 surrounded by some lettering, of which I can only make out NING * S; no idea what that could be. The obverse looks somewhat like a design on two pattern 20-cent pieces of 1875, but it is not that design because the numeral font isn't quite correct for that. Is there any foreign coin of approximately the 1860s that corresponds to this overstrike? Possibly even something associated with the US 20-cent piece, maybe a ca. 1875 splasher or Linderman midnight minting? Or is this just a token? Is it even a legitimate overstrike, or just some vise job PMD? It is raised, centered, and looks as legit as an overstrike on a heavily circulated coin can look, but I don't even know what the strike is, so it could certainly be a fake fantasy piece. Judge for yourselves.