Congress has not contacted anyone, I can point you to two veteran sites specificly containing what's happened. There is also a link on how to request classified records,.On this one http:/verteransinfo.org/korea.html
The second is a letter that went around awhile back, nothing came of this either.
A good site for locating and tracking other veterans of the DMZ is
I don't think you'll find anyone who has tried to get their records released to talk about it. The records are said to be in the Department of Defense not Department of the Army, what you get as a reply is usually "You volunteered, you signed the forms, don't ask again."
Good luck in your quest, most have enough already. You'll notice we finally got support for agent orange exposure in 1968 on the DMZ, and that was common knowledge.