I used M3 screws of various sizes. I liked the design but I changed a few things to make it more adjustable and I added a slotted bolt and nut to hold the cable without ties. I only had 10mm square magnets so I changed that and used small tabs that I heated and bent over instead of glue. I also put a few magnets in the base so that it will stick to a magnetic surface. Finally I added a couple of cams so that the paddles can be brought closer to the terminal.

The key works fine. I was going to use a brass standoff for the center conductor but it has not arrived so I just used an M3 screw with a couple of nuts tightened against each other.

There are slots to glue the wires into the paddles to neaten up the look but I have not done that yet.