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They actually found two of David’s seals.
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Not mentioned in your links above, so I did some googling and found recent mentions.
However, all the links I could find (i.e., Jerusalem Post) are too clunky to use, and near as I can tell, they're talking about recent finds of King David era seals.
Of course, there is a King David stela from Tel Dan, circa 800 BC, found in 1993.