Phew! Finally finished – which I often don't manage. Thanks to Micky for parsing 13d – I had worked out from the crossers the only possible solution, but hadn't seen how we get there, so thanks.
Most of all though, I want to say how brilliantly Paul has threaded solutions into each other in this puzzle – don't think I've ever seen a solution "hidden" quite like that before. Thanks, Paul, for a witty and, as usual, brilliant challenge.