Some years ago Professor Goren wrote to ANE and reported the patina was radiocarbon dated to the Hellenistic period.
It was not Iron Age II of Joash, nor was Joash the builder of the Herodian temple that was destroyed c. 70 A.D. by fire. As clever as the tablet appeared, it was not backed by the science of C-14 dating.
Oded Golan's property was searched by police and he was found to own numerous blank stone tablets taken from areas across Israel and was in possesion of engraving tools. Numerous people testified against Golan. The investigation was continued...the 60 Minutes news documentary show included a face to face interview with an Egyptian forger who said he worked for Golan. Golan had denied inscribing the tablet.
There were archaeology digs all over Israel. I passed them as I drove along highways and also saw them at previously excavated historical sites. Their black canopies set up to keep the sun off the archaeology teams were conspicuous. I am sure there are more pottery fragments in Israel than there is space to store them. If you go into an antiquities shop in Jerusalem to make purchases, you might be buying unprovinenced fakes, as they do exist, or you might have found the real thing. I am no expert on whether or not one can legally obtain and sell unprovenenced items, or whether you can set up your own dig and sell items. It is illegal to export antiquiites from Israel without a permit.
David Q. Hall