Thank you Mark! I think quite a few of us were thinking we must be going mad re 13D.
p.s. Jono and Chris - I quite like 19A. Try wheezing out the name of the London station, then you probably wont 'have a problem'.
Izzy -- 3D is a very convoluted clue. First word is a straight synonym, then an abbreviation, then a brilliantly disguised bit of this setter's penchant for 'primarily' clues towards the end.