Ottoman Bulgaria: 1876 (December). Cover to Istanbul franked with 2pi brown border irregular perf. of 1870 and 10pa deep lilac (isfila 81RV2) perf. 12 1/2 of 1873 Dulos stamps for 112 route-hours rate tied by double circle Ruscuk 81 (A&P type 5, R) handstamps. Reverse faint cds. Scarce 10pa colour variety on cover.
