MAURITANIA UPU ARCHIVE RECEIVING AUTHORITY SPECIMENS: 1940 10fr Madonna von Dux (Zu 150 / Mi 197). A strip of three affixed to piece of ledger page, without any specimen defacements, subsequently handstamped with large part 3-line "SPECIMEN / COLLECTION / MAURITANIE" in red-purple. Sent from the UPU in Berne to the Mauritania Post Office where they were affixed to the ledger page and tied by the Mauritania handstamp. Unique and philatelically important item proving distribution of this issue in normal unused and undefaced state as specimens through the UPU. Attractive & popular stamp, rare thus.
