I see that a number of people found this difficult. I found it really frustrating at first, because without having any way of knowing where to put the ones I had solved,each clue had to be done individually, with no help from the letters in the previously solved ones. However, once I'd solved about 10 of them, I tried tentatively sketching in three that I could fit together in the grid, and suddenly the whole thing became, by Guardian prize standards, remarkably easy. That doesn't, of course, mean that all the clues were easy, but none of them were disastrously difficult. A few people seem to have made the mistake that I made the first time I did ine of these jigsaw crosswords, that you can't start putting words into the grid until you have solved almost all of them. In practice, after a while you can find three or four that you can fit together, and while it isn't certain that you've got them right, the amount of coincidence needed would be so high that you probably have, so you can tentatively sketch them in. It will then probably soon become obvious that more of them fit in, making it just too much of a coincidence not to be right. On the other hand, in the less likely scenario where your tentative start us wrong, that will soon become obvious too, as several other words just won't fit, so either way you soon know whether you're on the right track. At least, that's the way it goes for me.
My only lingering problem is that I can't parse the wordplay for C, so any gentle hints would be welcome. First to be solved was E, but there was no specific first one in, since, as I said, I put several in together. LOI 7, which I liked, but my COD is S.