As it turns out, the team relied on two principal sources of information.  First, when the plaster was removed in the Drawing Room during an earlier investigation an area of broken and chopped bricks was discovered to the left of the existing ca. 1812 chimney. These broken bricks were discovered to be the remains of the bricks that had once connected the ca. 1764 chimney stack to the wall. They were created when the masons removed the stack in ca. 1812.