In Back Issue magazine #10, Mike Kaluta says about the inking in this issue, "On the splash page to issue #4, there is a truck barreling across the page. The license plates on the front bumper of the truck have got each artist's name and little page numbers to tell what pages they worked on."
UPDATE: Per email directly from Mr. Kaluta, the dashes on the license plates do not mean "through". Only the specific pages listed were done by those artists.
Color credits provided and confirmed by Anthony Tollin (DC Comics proofreader 1974-76/assistant production manager/color coordinator 1976-81) and Carl Gafford (DC Comics proofreader 1973-74/assistant production manager 1974-76).