I solved this, all except for parsing 23d (the solution and definition were obvious) and then came here. I was
very surprised at some of what I read. A large number of people evidently found it much more difficult than I did, which is unusual. A few of the criticisms of the clues I agree with, but most I find perfectly acceptable. For example, I not only saw no problem with 22a, but actually marked it as a good clue. I was astonished to learn that most people have never come across 3d: the full expression was still in occasional use when I was a child, if not later, though the (now universal) abbreviation to just the first word was by then usual. FOI 24a, which I found really easy. LOI and, despite its difficulty, COD, 23d. Boatman, if you read this, then despite the critical remarks from some others, take consolation from the fact that here's at least one solver who thought it a giod puzzle.