Just spoke to my dad over IM. (He types slow, but it's usually worth waiting for.)
The medic from his unit in Vietnam got in touch with him a couple years ago, and was saying how he remembers so little of what happened, because it's just so long ago now. Well, at the time, I was doing my honors thesis about Dad's Vietnam service and what it meant to him, so Dad had just dug up all his Vietnam stuff.
He still has everything.
He still has his uniform, which still fits. He still has his rucksack, which still works. 
Every map sheet they handed out, he still has. (They're all folded to the same size, to fit in the thigh pocket of his uniform pants so he could pull it out and see right where they were on the sheet. Some of them are stained red at the creases, from the red dust of the region where they were.)
He kept a notebook in his shirt pocket, and wrote down things like the call signs and passwords for the day. He made notes to write his reports, and calculated artillery ranges. He still has every one of those notebooks. Fascinatingly, one of the notebooks contains a lengthy handwritten piece, almost like a diary entry-- it is just after an action, and they're waiting for the helicopters to come pick them up, and it's hot and dusty and everyone else is asleep, but Dad can't sleep in the sun, and there are ants biting him, and he wants to go home. Dad read that to me, deciphering his handwriting, and shook his head. "I don't remember writing that," he said.
He still has newspaper clippings, letters sent to him, and even some of the letters he sent home-- his mom kept them, and returned them to him once when she moved house.
He also has 127 photographs. He had a cheap camera, and would take pictures, mail the film home, his mother would develop it, send it back. Then he'd label the pictures and send them home again. She kept them all and returned them to him as well.
And there are times when his memory conflicts with the artifacts he has. He doesn't remember ever complaining, but the diary from the notebook in his pocket is evidence that he did, sometimes, at least to himself. He found his reports of an action wherein some of his men were injured, and he remembered some of the details differently now.
But his medic, Ralph, really has nothing to reinforce or contradict the hazy memories. And, unlike Dad (who was the platoon officer and so was responsible for the maps and the compass and the radio), Ralph never knew where they were, really. He never saw it on a map. He was concerned with schlepping bandages around, not with what was going on. And he kept nothing when he came home. So he really doesn't know what happened.
So, Dad's ordered reprints of all his photos, and has made a few Xeroxes of the maps, and is labeling them so Ralph can look on the map and then see the pictures of where they were, and on what day. It sounds really cool.
So Dad's mostly just trying to get everything organized, both so he can share it with Ralph and so he can do something with it. As a historian, he knows how valuable primary source materials like that can be. But disorganized, in folders and plastic bags in a drawer, it's not very useful. He wants to put it in some kind of order, and maybe give it to a museum or something.
I'm trying to figure out how to digitize some of it and maybe make a worthwhile website out of it. I made one, years ago, but I didn't know what I was doing, and it was a weird little site in the end.
It does mean I have some of his pictures, though. This one
was taken just before his tour of duty ended and he left Vietnam. He had been planning to sign up for a second tour, but the commander believed that since Dad was his best lieutenant, he should be put doing the paperwork, because the paperwork was the most important thing about the war. Dad had just had a very successful tour, with almost nobody hurt or killed, and his guys all respected him. It made him bitter to think that anyone could really think paperwork was more important than that, so he left. Shortly after he left, the man just behind him, his platoon sergeant Robert Freitas, was killed in a friendly-fire incident, and several others of the unit were injured. Dad went to the Vietnam Memorial in Washington five years or so ago, and got a rubbing of Freitas's name.