Cowardy Custard is a musical revue and was one of the last Noël Coward shows staged during his life. It was devised by Gerard Frow, Alan Strachan and Wendy Toye. A book, also titled "Cowardy Custard", was published in connection with the revue, similarly celebrating the Coward image.
A book called "Cowardy Custard" was the inspiration for the Noel Coward musical revue, which was one of the last shows he staged during his lifetime.
I basically said the book was written first, but used words that I thought the system might not analyze correctly.