Beats me, my friend. You are way ahead of me on this one.
But anything which involves an Israelite Exodus from Egypt by sea prior to the Exodus by land pretty well qualifies as proto-Celt activity. I think those Israelites who left the tribe(s) after the overland Exodus should also be considered proto-Celts. We know these "defections" occured, but those people have been pretty well ignored by history. They are as Israelite as the rest, and are from both the Northern and Southern Kingdoms.