Response from Jonathan: Bill,

Leaf switches are actually easier to wire up. Where Cherry switches have 3 places to put wires, leaf switches only have two. You want your ground wire going to the bottom pin and the actuator wire for the button you are wiring going to the top pin. When the button is pressed, the plastic piece presses down on the top and connects it to the bottom which is what makes the connection. The acronym NOS just means New Old Stock which is basically a term for something that was bought new when the item was originally produced (in this case, sometime around the 1980s) and never used.

Hope that helps. Thank you for your question and good luck with your repair.