Finally finished it! Many thanks to Cockie for some useful nudges. My last solve was 29a, and having carefully considered every 4 letter possibility in Bradfords for the answer, it suddenly dawned on me that the answer was the headword I was looking under!! A brilliant feat of construction, with so many thematic references, I can only say that I am in awe of Charybdis. The Listener this year just keeps on getting better and better.