:Maybe in a footnote, though I'd like to see other editors' take on it since "Jackson" in this context may have been jocular. Men of Tomorrow. p. 197, notes that he'd changed his name legally, so the definitive answer would be in the public record as to whether he'd changed it to Jack Kirby or Jackson Kirby. I imagine the upcoming Evanier bio will specify, so it might be simpler to just for that. 

 :BTW, any movement on the Kirby v. Marvel section? I'd made some editorial comments at your suggestion.