The New Jersey "St. Patrick" Farthings are very difficult to locate with good surfaces and/or in high grade. Most examples are either well worn, corroded, or both. The producers of these coins intended for a brass splasher to be positioned so that the crown would appear golden, but rarely is the splasher in perfect position, and sometimes it does not exist at all.
The ideal example has smooth surfaces, lots of detail, a pleasing brown color, and a well-positioned splasher. The PCGS AU58 example illustrated above is one of the nicest examples known.