This engraving of King's Cross from the Illustrated London News reveals that the roof over the entrance and the small room at the left (seen the the photograph immediately below at right) were added after the initial construction.

http://www.victorianweb.org/victorian/art/architecture/london/54.html

Those sketches are drawing on Kings cross Station. The square front the station and the road between the Kings Cross and St. Pancras also on the Granary Square.