This knife is no longer in my collection
The Matterhorn Plus is one of the biggest models from Wenger. It has 9 layers, and only the Tool Chest Plus and the Giant are bigger. It is discontinued. Its key features are the magnifier, the universal wrench and the orienteering tool.
The orienteering tool has a ruler with inches and centimeters, and it has a small removable compass. Wenger introduced the orienteering tool in late 1985. Since then six different versions of the orienteering tool were made, so by the type of orienteering tool you can date the knife. The one on my Matterhorn Plus is the first generation, and because the second generation was already introduced in 1986 this dates my knife at 1985 or 1986.
external links: SAK Wiki