Ha! Having said I was going, I thought, 'Just one last look,' and I saw loads, so am now down to 15A (which I thought this a.m. would be herd + sag but isn't and the only thing which fits the letters is corsage, which doesn't seem to make sense) - ?? Hint or even answer appreciated so I can forget this.
And, like everyone else, 21D - though I have the letters H, O, S and Z unaccounted for. I also have plenty of answers unexplained but meh.