A new compiler for The Spectator I think, Firefly is the name used by Geoff Oxley for his Toughie crosswords in The Daily Telegraph - never tried them though.
Well, there seems to be a recording of the title by a group with that theme word in its name, but maybe I'm overlooking s'thing more obvious & important (I did wonder myself).....................
Almost done but have come to a grinding halt on 7d: Annoyed having tons to hold, ring man in depot (11). I have STO?N?E?PER. STOREKEEPER seems to fit the clue but ASKANCE at 18a is surely correct, so rules it out. No help from Chambers. Where am I going wrong?