MAURITANIA UPU ARCHIVE RECEIVING AUTHORITY SPECIMENS: 1940 KGVI Definitives 1s3d light blue (SG 57): The solitary value issued in 1940 in strip of three, each stamp perforated SPECIMEN in the usual manner for the UPU, affixed to piece of ledger page and further handstamped with 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. Markedly superior condition to the norm. Unique and philatelically important.
