I'm editing a work with the following passage, which describes seven signs:
. . . signs. Each had both picture and words. The pictures were an X on a rock, a cave mouth, a castle, a big tent, a tall tree, flames, and an open mouth. The words, however, were disturbing questions: ‘Mayhem and madness?’, ‘Certain death?’, ‘Vicious wolves?’, ‘Acts of carnage?’, ‘Razor claws?’, ‘Broken bones?’ and ‘Running with scissors?’.
The single quotes contain the exact text appearing on each sign. Is the punctuation used for the list of sign texts acceptable (American usage), or is an alternative better?