Dutch 20X139 shell case

  • I have a Dutch made 20X139 rimless steel shell case which is headstamped like this: “20X139 DM1 A1” over “LOS NWM- 2-102-X” The fired primer screw is marked: “DM64” over “LOS IWK-1-14”. What is the precise date of manufacture of this shell case??? I know that in Holland only the “NWM” company manufactured 20X139 ammo between 1980-1998. Thanks in advance for any help, Liviu 09/14/08