Caravaggio, it is a slow road to recovery - still not too steady on my feet, so collecting RT is not an option at the moment. But it did finally arrive in post!
Quite a hard one this week. 18A was annoying for the reasons stated in earlier comments. 24A (dun)was something that I was not aware of; as indeed was the "instrument" in 11A. So I did learn several things from this particular crossword.
Particularly liked 8A, 20A & 22A!!