To pay new letter and parcel post rates to Germany that had gone into effect in 1916, Luxembourg added 17½-centime and 87½-centime denominations to the Marie-Adélaïde definitive issue on March 1, 1917. The cover shown here was posted on the first day of issue of the 17½-centime Marie-Adélaïde definitive, long before cacheted first day covers came into vogue. It’s addressed to “der firma gebrüder Senf” [the brothers Senf], a well known stamp dealership in Leipzig, Germany, and was censored and passed free at Trier. Sent by Victor Hoffman, 6 rue de l’Arsenal, Luxembourg, the cover is backstamped at Leipzig, March 3, 1917. The 17½-centime definitive pays the 20 g letter rate to Germany that had taken effect on August 1, 1916; the 25-centime definitive pays the registration fee.
Sometimes what at first glance appears to be a mundane cover with a common franking turns out to be a treasure.