French World War I 37mm artillery shell. Headstamp Markings Breakdown, 37-85: Denotes the 37mm caliber and Model 1885 design.1.18: Date of manufacture, meaning January 1918.PDPs: Manufacturer code indicating Parc d'Artillerie de Paris (Paris Artillery Depot).279: The production lot number.Flaming Bomb Stamp: The French military acceptance and inspection mark.