Multi-function knives have many useful tools in them. This one includes a CW key too.




Plastic knob was attached to sewing tool hole with a screw.




Keying contact was built on the cork screw tool, using heat-shrink tube and aluminium tape. Unfortunately that means you must have a separate cork screw for wine bottles.




Before putting the knife into pocket the keying wire is wound around the knob and the 6.3mm plug put under the blades like this.



See & hear the key in use: