While I enjoyed this radio adaptation (not withstanding the depressing ending), I couldn't help remembering a British black COMEDY with a very similar plot - from 1957 "Your Past is Showing"  (also known as "The Naked Truth").  Perhaps it would be best to use the summary shown on IMDB:  "A very British comedy about a blackmailer and his victims.  Nigel Dennis (Dennis Price) publishes a scandal magazine. But for each story he writes, he first approaches the person whose scandalous behavior is described (or rather implied, to avoid any libel suit) and says he will suppress the story in return for money. Several of his victims first decide individually to kill him instead of paying, but fail in amusing ways. Then they find that to protect their various secrets they must now join forces for a rather different purpose...".  Leave it to the British to find humor in murder & blackmail.  The victims include a young PETER SELLERS, TERRY-THOMAS (a favorite of mine), as well as other well-known British actors from the 1950's and 60's:  Shirley Eaton (the gold-painted girl in James Bond's "Goldfinger"), Peggy Mount, Miles Malleson, Joan Sims - well, at least they're well known if you are a fan of vintage comedies from "across the pond"!  If you have 88 minutes to spare, check it out.  In fact, I think I'll locate my copy now and give it a watch.  Until next time...pleasant dreams!