Sometimes working in the conservation lab is like being in National Treasure. A map from 1775, showing property division between Richard Penn and Mary and Sarah Masters, came into the lab needing paper mending. The map had been mended previously with paper similar to paper the map was made from.
On a hunch - I took the map to the light table. . . . . . and secrets are revealed! The map was mended with a letter signed by a Chew - probably one of the Bens. It discusses building materials including boards and white pine posts and the construction of a fence around Turner Camac (of the wooden street in Philadelphia) and Richard Penn's property.
And even though it doesn't reveal the location of the Knights Templar Treasure, it's still really fun to work in the conservation lab.