This was as far east as Graham and I would venture today with the focus of our activity to document the doomed GNR/GER ‘Joint’ line that ran between Spalding and March. Horsemmor signal box was located to the east of March on the Ely line where it crossed the B1099 Upwell Road. This was only a short distance from March South signal box with the next one in the other direction being Stonea. Opened in 1899 by the Great Eastern it was unusual in having a covered landing and a window arrangement of small panes above tall that appeared to be unique for this particular design of box. The box shut on 13.11.88 with an anonymous grey relay room and full barriers replacing it, however, the structure was carefully dismantled and is now located in a reclamation yard at nearby Murrow, see….
https://www.ontheupfast.com/p/21936chg/30044473940/former-horsemoor-signal-box-murrow