This probably isn't the answer you're after, but this is how a Vietnam veteran I work with opened up a little about his service.
When I picked up my Colt AR LE rifle at lunchtime a few weeks ago, I brought it into the shop to show it off before I put it in my car.
When I let John (the veteran) inspect it, he said something along the lines of "come out here, I wanna show you something) and we walked out to his work truck.
He opened up the laptop he had in the truck and showed me a whole bunch of scanned photos from his time at a place called "Marble Mountain" back when he served in 'Nam.
He was a side door gunner on some kind of dual-rotor copter...can't remember the name of it right now.
Anyway, It was neat that he was willing to share the photos with me, since he doesn't talk about his personal life that much. He's one of the coolest guys I've ever worked with, though.
Anyway, the mere presense of an AR rifle got a Vietnam veteran to talk to me.
Scott