brendan (and jono): re 9a, I think the punctuation points to the second half being the definition (and it better suits the thematic nature of the crossword), but I agree that it’s not wholly unambiguous!
Rogissimo @26, my memory of the Brendan puzzle results from a puzzle by “Jay” (if you search the forum, it’s #11) which deployed one such implement and caused some discussion at the time ;-)
Thanks Jono and Rogissimo. None the wiser I'm afraid, but will continue to scratch my head although it feels more like I am hitting it against a brick wall!