cover -- 1919 (31 Mar.) O.A.S. envelope (repaired tear at lower right) to the North Russian Expeditionary Force in Onega showing a fine strike of the rare "FIELD POST OFFICE P.B. 99" c.d.s. struck at Kola, showing "FIELD POST OFFICE/P.B. 12" arrival c.d.s. (9.4.19); countersigned and with censorship h.s. Photo