I don’t know the true origin, but it sounds like Scots to me. “Aw” = “all”, and “but aw” would presumably be like “after all”, or “though” in Bristol (or maybe

I don’t know the true origin, but it sounds like Scots to me. “Aw” = “all”, and “but aw” would presumably be like “after all”, or “though” in Bristol (or maybe Yorkshire?) dialects.