@JCB What do you mean by check bills? Do you have questions about currency? Try this forum of ours (at CT): https://www.cointalk.com/forums/paper-money/
Does it JUMP to the magnet when it gets to within about a half inch or so? Netherlands East Indies Duit, made for use in the Indonesia area on the other side of the globe and has absolutely nothing to do with New York. (In fact the English drove the Dutch out of the area in 1690, thirty years to a hundred years before those coins were even made.) Not you fault people market them this way because the Dutch first settled the New York area, and most people aren't going to give a hoot about a Dutch coin for some place on the other side of the world. But these things are very common and cheap, and they can get a lot more for them by giving them a made up colonial US "mystique".