Series Number Id: GSGS 2742; Sheet number: 36c SW; Edition number: 9a, Location: Research Collections; Fonds: WW1 Trench Maps: France; Box number: PC08; envelope_number: 201, Manuscript on face: markings for advance south Lens; Stamp on reverse: 12th Canadian Infantry Brigade - April 22nd 1917; Repaired; some stains and holes.