Series Number Id: GSGS 2742; Sheet number: 36a NW; Edition number: 6, Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC08; envelope_number: 204, Manucsript on cover: 250th [Tunnelling] Company RE; Manuscript on face: small red circles on road junctions - for demolition craters 1918?.