I thought you'd finished, AJT. I worked out 16D from peterm's help. The four towns start after FA, and it's an I in parentheses, not an L.
I can't see where 6D (for which I have the only possible answer) fits. Nor 4D - for which there are two possible answers, neither of which seems to fit (after the i of tit?).
Then it's just the bottom right-hand corner left. Did I say "just"?