cover 1906 (16 Aug.) ¼a. Service Post Card (light toning) from Calcutta to a military accountant, Chumbi showing a good strike of the rare "FIELD P.O. NO. 26/18 SE/06" single-ring d.s. struck on arrival, slightly over Calcutta c.d.s., with "BASE OFFICE" (17/9) single-ring d.s. adjacent. Photo