cover 20c. on 50c. violet with 2c. on 5c. (2) and 8c. on 20c. on 1917 registered express censored envelope ("LEGAZIONE D'ITALIA A PECHINO" cachet in violet on reverse) to Rome (13.2.18 arrival), cancelled by "R.R. POSTE ITALIANE/PECHINO-CINA" c.d.s. (22.11.17), the 20c. on 50c. has a number of perfs. at left trimmed by scissors separation which does not detract from what must rate as one of the most important covers from the Italian P.O. in China and the only recorded example of the 20c. on 50c. extant on cover. Enzo Diena certificate (1988). Sass. 1, 4, 6. Photo in colour on front cover