You could scan or photograph (if your digital camera has a high enough megapixel rating) the pieces of newspaper on the back.
Then to remove the paper, I would get some laminating sheets from the office supply store, cut them to fit over specific areas of the back, press them onto the paper, burnish it down with a bone paper folding tool (called a bone folder) or something similar, then peel the film away, taking the paper with it.
Most of these laminating films are acid free and archival and will preserve the paper for a very long time.