The pictures posted by Luke show the insignia as worn by the Air Force, i.e light grey/white on dark blue background. The Army wore similar insignia, but on olive green. Note that the bottom of the Staff Sergeant's crown curves upwards. As far as I know, this particular shape was only used for the small insignia worn on shoulder slides for field- and fatigue uniforms, as well as overcoats, for a very short time ca. 1973-75. At all other times the bottom of the crown was straight.
Chevrons as insignia of rank for NCOs were introduced when the Norwegian government in exile started to rebuild our armed forces in Great Britain during WW II. The soldiers were issued British uniforms, for Army officers with Norwegian rank insignia worn on the collar. The NCOs, however, wore British style chevrons, the crown for Staff Sergeant and cannon for Gunnery Sergeant also being of British pattern. These ingignia were introduced January 1943, the badge for Gunnery Sergeant in September same year. The ranks were as follows:
Stabssersjant - Three chevrons with a crown above
Artillerisersjant - Three chevrons with cannon above
Sersjant - Three chevrons
Korporal - Two chevrons
Visekorporal - One chevron
After the war Norway continued to use British style chevrons, but the badge for Gunnery Sergeant was abolished. However, from 1945 to1954/55 the chevrons were worn point up, with the crown for Staff Sergeant placed below. Norway introduced new service uniforms in 1954/55, still of the battle dress type for rank and file, but with slightly altered cut and in a more olive green color compared to the previous one
Rank chevrons of a new style were introduced in 1955, worn point down on both upper sleeves of the service uniform. These chevrons were 75 millimetres wide, i.e. considerably smaller than the old British ones. Oversersjant was introduced as a new rank between Stabssersjant and Sersjant, wearing three chevrons topped by a straight bar. The insignia for Stabssersjant was changed at the same time to three chevrons topped by a straight bar with a royal crown above. The chevrons were white for Infantry, Cavalry, Engineers and Signals, yellow for all other branches in the Army. The Royal crown worn above the chevrons by Staff Sergeants was always yellow with a red cap inside, regardless of the color of the chevrons. The Air Force wore white or silvery chevrons.
Small versions of these chevrons could be worn on shoulder slides or breast/pocket patches on garments where sleeve chevrons were not suitable. The ranks of Stabssersjant and Oversersjant were usually given to Sergeants with a record of several years of service, usually with a technical or specialist background. Both ranks were abolished 1 July 1975, and those holding these ranks were promoted to 1st or 2nd Lieutenants respectively.
From 1983 chevrons were no longer to be worn on the sleeves. They were replaced by small metal chevrons placed point down on the collar of the service uniform. All rank insignia, including chevrons, were of gilt metal for all branches except for H.M. Royal Guards, the War Academy and the senior level of the Non-Comissioned Officers School who retained silver as metal color. Finally, the rank of Visekorporal was abolished from 1 January 1993.[/i]