Congres notepaper with the ½d. - 2½d. PUC low values cancelled with 2 Postal Union Congres London 10-MY-1929 (1st. day of issue) cds's, as supplied to the Delegate's secretaries at the Congres, fine (bottom part notepaper cut-off, not affecting stamps or cds's), a rare piece cat.v. £ 1400