I had bought a signed picture of the Four Horseman of Notre Dame. It was a vintage photo, silver gelatin print. When I bought it, it had been torn in half and glued to cardboard. It also had chips missing from all corners and in spots on the photo. The signatures were actually in good shape. I contacted the Philadelphia Art Museum and they sent me to their conservator.
http://www.ccaha.org/ They charged me to look at it ($75 I think) and sent me three price options. I choose the most expensive which was $1000. The picture came back and you could barely tell there was ever a problem. I ended up selling it in a major auction house. (with full disclosure) I got over $3000 for it over 10 years ago. I wish I still had it! I didn't even keep a scan. I tried to ask for one a few years ago but they wanted too much to find me one. Anyway, I was very happy with their work.