1922-29 Wmk Multiple Script CA KGV ¼d, ½d, 1d, 2d, 4d, 5d and 6d strips of three optd ‘SPECIMEN’ affixed to four pieces of ledger sheet with portions of ‘SPECIMEN/ COLLECTION/ MAURITANIE’ UPU receiving handstamp in magenta, slight toning. Unique, from the recently released Mauritania UPU collection