For the exterior trim, a surviving ca. 1764 window was used as a reference.  This window was used for both the recreated ca. 1764 and the ca. 1797 windows because the windows in both periods were housed inside of the window's rough opening.  The similar form of window would have therefore resulted in a similar type of window trim.  For the window sashes, the design was largely based on the fairly standardized sizes of window glass and window frame components in the late 18th century.