#1 reprints the Batman story from Detective Comics (DC, 1937 series) #395 (January 1970) and the Manhunter story from Detective Comics (DC, 1937 series) #437 (October-November 1973)
#2 was to reprint the lead story from Superman (DC, 1939 series) #236 as well as continuing the reprinting of the Manhunter serial.
#3 was to reprint a Phantom Stranger story and continue the reprinting of the Manhunter serial.
The cover to #3 appeared in Cancelled Comic Cavalcade (DC, 1978 series) #2.