The next new Doomsday + 1 story appears in Charlton Bullseye (CPL/Gang Publications, 1976 series) #4-5, 1976.
John Byrne revealed on his message board (http://www.byrnerobotics.com/forum/forum_posts.asp?TID=37083&PN=1&totPosts…) that the pencils were done by a fellow Art College student named Doug Bevan, though Byrne redrew some of it including the splash page.