Butterley Company correspondence file on the development of coal workings in Plumptre area Including correspondence and estimates for driving stone heads, Jan 1936, with loose plan and sections of mineral area between Bailey Brook and Eastwood, showing Plumptre estate, Sep 1935, plan and section of Bailey Brook Colliery development of Soft Coal, Jan 1936, and plan of mineral estates near Eastwood Sep 1935-Jul 1941