Thanks, gustabo, but that suggestion didn't work. However, scook, yours did! Rolling back to 23.7 re-instated the Style Dials, and then when I updated to 23.8, they miraculously appeared again!
(Btw, gustabo, SHOUTING worked! These are the first responses from anyone in almost 3 weeks, and within minutes the problem is solved! Sorry if the loud noise disturbed you!
Thanks, folks. Much appreciated!
Ted