An interesting article I found on the AP is revealing that ever since the Ashkar manuscript, which is one page of the Song of the Sea, was photographed and published in 2007, it caught the eyes of some others, who were able to match it with it's other part.
The two who saw this were Mordechay Mishor and Edna Engel, both of whom are Israeli paleographers. They both recognized that it was similar to what is referred to as the London Manuscript.
They were both displayed in Jerusalem, reunited, on Friday. These are both 1,300 year old fragments and, are part of the Hebrew Biblical manuscripts.
It is not known how the parts became separated, only that they are finally back together now.