As digital photographers, we have all gone through the learning curves associated with our gear and the software. I often times try to use this knowledge for new and interesting ideas. One such idea is to re-touch older images, using Photoshop.
I like to actually take an image of the photograph that needs re-touching, at the beginning of the project. This is better than most scans that I could make because the raw file from the camera will be massive in size. Make sure to pay attention to the white balance to ensure color correction is as perfect as you can get it. I like to use two flashes set at 45 degree angles to the print, by the way.
Next, make the time to select and then try out the right tools for the edits you need to make. For example, cloning (with the clone tool) may work for some details, but not others.
Re-creating any the lost detail is the hardest part of the process. I like to lean on my art background as much as possible, just to make sure that all of the little things look right.