Does anyone know when colt started using the hard blue plastic cases instead of the boxes? I recently purchased a 70 series gold cup with a 70Nxxxxx serial number (nib) and seller swears that the hard blue plastic case is original to the gun. Anyone know what year they started using plastic cases? I just purchased another series 70 with a later serial number in a carboard box. Did they ship both ways for a while or was my first seller lying? please help