My gggrandfather was a prisoner at andersonville. I have his document stating he had a lifetime membership in the Andersonville survivors assoc. The document is fading in certain places and I can not find a value on this document. I know what it is worth to me but, do I insure it? If so, for how much. Do I have it preserved? Who do I contact and who do I trust? Most prisoners only lasted a few months. My gggrandfather lasted 13 months, (according to the document). How do I find out more about this???