I agree that there may well have been, at least historically, scots who have claimed descent from the lost tribees of Israel. There may well still be some who do, involved perhaps with the British-Israel movement or the Christian Identity movement. This theory is most abviously promulgated at the moment however by some of the less pleasant adherents of the religious right, i.e. white supremacists.
That aside, are you saying that the actual bit f tecxt in question, i.e 'Thence they came, twelve hundred years after the people of Israel crossed the Red Sea, to their home in the west where they still live today.', explicitly identifies the scots as being descended from the people of israel and could not possibly be parsed as a 'time mark' or a way of dating the scots' entry into Scotland?
TTFN,
WK