Telegraph block instrument (sending/receiving)
Telegraph block instrument; SR Standard (stamped "SR 31") absolute pegging/non-pegging 3-position/3-indication type. There are 2 vertical banners (black) enamel-plated "DN/UP Goods Line" (DN: top-mounted/UP: in circular brass bezel). Enamel-plated "Bricklayers Arms JC", below which is a circular bakelite-commutator with a "Line Occupied" slide-bar commutator-locking mechanism and to LHS a small brass release-button. These instruments were later contracted out to R.E. Thompson?