I don't know whether this applies to the version in the Observer itself, as I do the downloadable version of the Azed. However, in that, the clues for 20 and 21 down are transposed. I figured I'd save you all much pulling of hair if the same held true for the printed one.
I'm afraid you have to subscribe, Cheaton. If I remember rightly, it costs �25.00 for a year's access to all the Guardian and Observer crosswords. You'll probably find out how to join by Googling 'Guardian online' or some such. Having been a faithful reader for decades, I finally gave up on them - and their views - over the past couple of years and ended up buying them only for the crosswords! Cheers