Beck, in a page by page anaylsis of this story (printed in Alter Ego #129 (November 2014), specifically states that Parker wrote the story, he (Beck) did the layouts and all figures, while Costanza supplied most of the striking backgrounds. Credits above revised to conform to this statement.
Inker revision from Beck to Costanza, per P. C. Hamerlinck, in Alter Ego #126 (July 2014) and added by Craig Delich. According to the article, this story was the FIRST Beck-Costanza art collaboration.