Rule as well inked the prolific Kirby on Western stories in "Gunsmoke Western" #51 and "" #86 (Sept. 1959), romance stories in "Love Romances" #85 (Jan. 1960), and war stories in Battle #66-67 (Oct.-Dec. 1959), plus many covers across all genres. Rule's last known confirmed credit is inking Kirby on the five-page story "What Was the Strange Power of Simon Drudd?" in "Tales to Astonish" #10 (Jan. 1960). Some comics historians theorize he may have been an inker on some portion of Kirby's landmark comic "The Fantastic Four" #1 (Nov. 1961), for which George Klein is the generally recognized, uncredited inker. The standard Grand Comics Database, for example, lists the inker credit as "George Klein?; Christopher Rule? ... George Klein, or Chris Rule have been suggested as the inker but there is no consensus." Others note the long lag time between Rule's last confirmed credit and the "Fantastic Four" premiere. Rule inked Jack Kirby on stories in comics including: