Netherlands 1917 Registered Military mail cover

Envelope from the Belgian Artillery School at Harderwijk to Kakamocka French Gabon and cancelled Portvrij Franc de Port. Militaires Etrangers Internes Dans Les Pays-Bas with Harderwijk registered label routed via London with control postal Military label and Opened by Censor 902 cachet routed via Loango. Fine & Rare destination item. (pt)    ID: 10126