This is an actual Forgan stamped hand hammered golf ball. "In the 1860s, Robert Forgan devised a criss-cross mesh pattern. This pattern was copied by most of the gutta percha ball manufacturers and became known as the Forgan Mesh or Random Mesh pattern." The Story of the Golf Ball (2003) by Kevin McGimpsey.
True Forgan stamped hand hammered balls are very difficult to find. For obvious reasons, it is often nearly impossible to find a stamp on a ball that was then hand hammered a couple hundred hundred times. But the offered ball has a findable and somewhat readable "Forgan" stamp.
This ball was part of the famed Jaime Ortiz Patino collection, which sold at Christie's in 2012.