Thanks AJT. Had 41a, but if "logician" is not the extra, then I'll have to go hunting again.
sudokulover's 2d brings me back to the 4d 17a problem -- duplicates. Perhaps I have 18a wrong.
Thought I had the Kettle sorted out, but when I fix one letter I get another duplicate. No wonder I hate bouillabaisse.
Yes, "My head hurts!" & I'm going to bed.
Bon nuit.