>>In other words even if this stone exists, even if it really is in Hebrew the odds are ENORMOUS that it postdates Columbus by a considerable margin.<<

Now this is mega speculation by a super skeptic.

1. The article does say there is a stone and where its location is. I would suspect that the locals can take you right to it. If it doesn't exist they will get a good laugh.
2. The article says it is written in Hebrew. Make sure when you visit the site you have a hebrew expert with you. In less than a minute that expert will determine if it is hebrew or rat scratchings. Speculation remotely about the results doesn't count.
3. Supposedly the stone is still in situe. A serious archaeologist could determine that rather quickly. New dating techniques WILL zero out speculation (patina-etc).

Now teams cannot just go around looking at every claim like this. Economics like all activity on the planet determines whether resources and people should be involved. With modern communication and google it should be rather easy to handle 1 or 2. Ocate it and have a local take good digital photos from numerous angles. On line transmission and the best of the best hebrew and archeology types can finish 1 and 2. # is a different problem. However it is ONLY operative if 1 and 2 return a positive result.