It would be interesting to cast actors from previous eras as superheroes today. Didn't Millar do a piece about Orson Welles considering playing Bruce Wayne?
Warren Oates in his prime would've been a good Wolverine. Burt Lancaster as a Terminator Slade with Kirk Douglas as Deadshot would be my dream 60's team up. Young Shirley MacLaine as Harley, maybe? Tony Curtis as the Joker.