Jack Kirby pencilled the main figures on page 1 and the last page, with the possible exception of the final panel, confirmed by Dick Ayers. Carl Hubbell may have inked the last page and possibly drew the Bull McGiveny figures on page four, panels two and three. Info per Nick Caputo, who discussed this story on his blog:
http://nick-caputo.blogspot.com/2014/06/the-unknown-art-of-carl-hubbell....