cover 1890 (7 Aug.) registered envelope to Cologne bearing perf. 13½ x 12½ 1mk. (1/-) deep green/carmine and black (II printing) cancelled by double arc d.s., showing arrival c.d.s. (8/8) on reverse. Fine and very scarce "einzelfrankatur" showing correct usage. Signed Drahn. M. 19Ab. Photo