I delved back into the BBC’s archives via the new online archive of Radio Times listings, looking for Lovecraft items on the BBC. The item below is one of their earliest. It perhaps exemplifies why some people had a bad reaction in the 1970s to what they thought was Lovecraft. Because in this case, the nation would have been listening to a 1957 Derleth story wrongly attributed to Lovecraft…

Study on 3
The Horror Story 1: Gothic Tales
20th-century Gothic is illustrated by H.P. Lovecraft’s story The Gable Window, read by EDWARD BISHOP.

So far as I can tell “The Gable Window” was wholly by Derleth, only being very loosely based on Lovecraft via one of the brief story ideas found in the Commonplace Book.