I wish I had some time to research and comment on these Gath(ish) things. In a couple of recent posts Aren Maeir has called our attention to a bulla (“Belonging to Azar, son of Gitti”) and a Persian Period ostracon (ln.3 “on 22 of Elul BGT”) that may (or may not) refer to Gath or someone form Gath. And then there is the LMLK GT seal that I noted the other day and on which Aren wrote a more substantive post. If you haven’t already, check all this out for yourself.