I think the important thing to understand is "oldschool" is not necessarily old-fashioned. Look at the people Sharp mentions as his inspirations - Newman, Dean, Brando - actors who generally portrayed characters with an anti-authoritarian streak. I don't think it's about making Hal "outdated"; it's more about giving him a distinct charm and vibe from that era that helps distinguish him as a character.
This makes me think I'd be down for a period piece Hal story...something like New Frontier.
Avatar: Here's to the late, great Steve Dillon. Best. Punisher. Artist. EVER!