Spot on McGrath. this extremely informative site on Stella Gibbons confirms that it was a real place. She was originally going to call it something quite different but was talked out of it by someone who knew a real farm called Cold Comfort.

The site also mentions how pleased she was when Kenneth Williams was chosen to read the book on the radio. I'm pretty sure you won't find the recording available from any retail outlet at present. The BBC may re-release it sometime in the future. It might be worth trying a library, there may be an old copy lurking in a stack somewhere.