unused Block of Four 1912-13 ½a. yellow-green block of four with interpanneau margin at foot, variety overprint double, fine mint. B.P.A. Certificate (undated). S.G. O76a, £400

Details
unused Block of Four 1912-13 ½a. yellow-green block of four with interpanneau margin at foot, variety overprint double, fine mint. B.P.A. Certificate (undated). S.G. O76a, £400