Thanks for the tip on BBC 7 radio, Harry. I'm listening now to The Man from Munich.
In the '70's I enjoyed the CBS Radio Mystery Theatre which was a program in the same vein as those decades earlier. They were nothing special about these but I enjoyed them. You can find a number of them here:
http://www.archive.org/details/otr_c...mysterytheater
I also enjoyed listening to short wave broadcasts for many years until that went into decline recently. And I even remember being pleasantly surprised when I once tuned into a low-power AM radio station broadcast of a woman reading from a book. In contrast, I almost never listen to audio books - I prefer to read them. There's something about listening to a radio production which is really quite satisfying but I can't put my finger on the difference.