Back in the day editors would draw directly onto a photograph to crop it, normally with a black grease pencil. There really was no thought of preservation or organization at the time. Negatives and photos, once they'd served their purpose, were often gotten rid of or given away.
One can also find white marks, which look something akin to lines of white-out. The white lines can be removed simply by using a little water and a cloth to wipe with. Be careful not to drench the picture with water. Although this will remove the lines, if the photograph is old enough, it will also develop cracks on the surface of the picture.
Original
Restored
More to come...
