This neat, gray, GB Victoria, 1873, 6p, Plate 15 issue was used at the British Post Office in Constantinople, Ottoman Empire, some time between 1873 and the late 1870s! Though a bit off-center, and with what looks like a bit of toning, it's in good-very good condition! A great, black, "C" bar letter cancel(65-70% complete) was applied!<div><br><div><div><br></div><div><br></div></div></div>