Who's This? They call him Balloon Buster, but he's really Lt. Steve Savage, it's just that Who's Who did so hate to use a real person's name (Jimmy Olsen is under E for Elastic Lad, and Alfred Pennyworth under O for Outsider, a monster he became pretty rarely). Steve Savage, Balloon Buster, whatever. He captured all our imaginations thanks to a wonderful Joe Kubert illo on Volume II's third page.
How you could have heard of him: The match-ups with Enemy Ace were reprinted by Enemy Ace Archives (vol.2) and Showcase Presents Enemy Ace, and James Robinson made Savage a descendent of western hero Scalphunter in a Starman story.
Example story: Because it had to be the Kubert issue, I've chosen All-American Men of War #114 (1966), conveniently reprinted in Star-Spangled War Stories #163 (1972).
Who else? Who's Who Vol.II includes a few other lesser lights, but are they "lesser" enough to show up in Who's This? Bat Lash has recently appeared in All Star Western. Ben Boxer, maybe? Or are we all Kamandi experts? If you have any requests, let me know and I'll hit them on the second pass. For now, I'll be perusing Vol.III...