MY thanks to all who have offered helpful suggestions in VIQR. Unikey looks promising as an IME (I am waiting for my wife to tell me what the buttons say !), and a list member has kindly offered off-list to have a go at creating a TECkit map as and when he has time. So let us not expend further effort on this topic for the time being; it looks as if there are at least two fairly straightforward solutions.
** Phil. -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex