Head - Gung-Ho
Arms - Dogfight
Torso - Airborne
Waist - Duke v22
Legs - Roadblock

Backpack - Mercer
Rifle - Marauder Inc.

Gung-Ho's original head is relatively difficult to use in making customs, unless you're making a Marine. There aren't many units other than the Marine Corps which wear the same utility cover that they do, but the Navy Beachmasters are one such example. Beachmaster units support amphibious operations by controlling watercraft and cargo near the shore, and assist in surf salvage and personnel evacuation. Longshore is part of the second wave of Sea Devils, a GI Joe subteam that specializes in amphibious, littoral and riverine operations, so a Navy Beachmaster is appropriate for the team. Gung-Ho's head actually has a hairline sculpted in - sideburns are clearly there, just not painted. The decision to make him bald must have been made relatively late in the process.