I know these posts are a bit old, but I'm a genealogist and before you use any old photos, make sure you scan them and put them on a Computer disk or USB drive. There are places that can do that for you if you don't know how. The reason I say this is, there may be long lost cousins/other genealogist, or other family members that would love to have a copy of the photos. Putting them on USB or disk will allow you to share the photos with those other family members, and if the photo you use goes bad in the scrapbook, you have the photo saved and can make a new copy!
Always save your photos, in this manner. Especially the really old ones, as they are so rare, and being able to share those with other family will be a gift they will always treasure.