This is a perfect example of why digitizing the images is critical. While it's always best to have the original photo when possible, ALL photos and negatives will eventually fade and fall to pieces. A digital file, however, can be burned to disk and multiple copies can be created and shared with all those relatives. If something happens to person A's copy, person B can created a new disk for them. No deterioration.
You can find a line of quality archiving materials at Light Impressions. I would also find a good book on archiving and get familiar with terms and procedures. LI's site is at http://www.lightimpressionsdirect.com/
Good luck and make copies of those documents!! :-)