On Jeroen's Victorinox Blog, that's have à timeline of Victorinox current toolshttp://jeroensvictorinox.blogspot.fr/p/victorinox-tools.htmlBy elimination we can deduce that the date is from 1951 to 1961 like said Jaydar
By elimination we can deduce that the date is from 1951 to 1961 like said Jaydar
1959-1960, trust me on this. Pre-1958 this knife would have exposed rivets. 1958 the rear of the blade would say "Victoria Officier" instead of "Victoria Officer Suisse". Circa late 1960 this knife would have a thin aluminum spacer between the pen blade and the divider; this knife has a thick nickel silver one indicating that it's a bit older. There are a lot of minute details that are not documented that contribute to dating these knives.
BTW, this logo goes back a ways. Here's the same logo on a Spartan from the mid 1940s:(Image removed from quote.)