cover 1919 (26 May) envelope regitered "via Hong Kong, San Fransisco et Puntarenas" to Costa Rica, bearing 1908 15c. and 1919 2c. on 5c. ( 2) and 10c. on 25c. with "MONG - TSEU - CHINE" c.d.s. and showing framed "A R" h.s. alongside, various transit d.s. on reverse. Rare and unusual. Photo