Make a bunch of copies and store them in different places. Every benefit he could get from the VA starts with that paper. Also, here are the addresses to get his medals replaced:
Army
Where to write for medals National Personnel Records Center
9700 Page Avenue
St. Louis, MO 63132-5100
Where medals are mailed from U.S. Army TACOM
Clothing and Heraldry (PSID)
P.O. Box 57997
Philadelphia, PA 19111-7997
Where to write in case of a problem
or an appeal Commander
U.S. Army Human Resources
Command Attn: TAPC-PDO-PA
200 Stovall Street
Alexandria, VA 22332-0474
Here is the 25th Infantry Division Association web site. It might help you to fill in some of the history your dad lived through and is a good place to ask questions.
http://www.25thida.com/
1/14th Unit history:
http://www.25thida.org/14thinf.html