According to Schaffenberger in a 1998 letter, many covers at ACG were penciled and inked by him, but signed by Pete Costanza because DC editor Mort Weisinger (for whom Schaffenberger worked on the Superman Family titles at that time) did not want him drawing superhero covers for other companies.
house ad for Adventures into the Unknown (American Comics Group, 1948 series) #154, featuring Nemesis
Letters submitted by Dwayne Meisner; Chris Stanley; Colin Berry; Guy H. Lillian III; Richard Hoppenstedt
Statement of October 1, 1964
Average monthly paid circulation during preceding 12 months: 179,250
Actual sales for issue nearest filing date: 196,000
Owner: Best Syndicated Features, Inc., 2nd and Dickey Streets, Sparta, Illinois; Frederick H. Iger; H. Donenfeld