I've been feeling distinctly low energy since well before Christmas, so posting here has been desultory. Sorry. I have been listening to a lot of old radio stuff on YouTube, acting like hi-tech fogey. Here are two BBC radio plays based on stories by Robert Westall. Having read them both I can testify to their faithfulness.
'The Wheatstone Pond' is the story of an antique dealer who hopes that the eponymous pond will yield a few interesting items when it is drained. Instead, horrors of the past are dredged up. The story was originally published alongside 'The Stones of Muncaster Cathedral' in a single volume. The latter story is also about ancient horrors striking deep into modern lives, and concerns a steeplejack and a very unpleasant gargoyle.
Both are good winter listens. The poster has added commercials, but I don't think they are overly intrusive.