Stapler CW key
Attaching papers together with a stapler is a boring way to spend your time. So I suggest you modify the stapler for Morse code use instead.
The gap between contacts is adjusted with screw and bolt. The original spring is usually too heavy, so it must be cut shorter, bended or replaced.
Underside details. I used this key in the SCAG Straight Key Day (winter 2007).
See & hear this video clip from modern office: