To build the Ignition Key, I used a cheap motorcycle key, a volume knob and a 5 position rotary switch which cost me about $3.96 in total (and there are still 9 knobs left from 10 pcs purchased :) ). First I removed the springs and the plastic part that prevented the key from fully rotating. Drilled a hole on the knob and using ca glue glued it to the plastic part of the key (you can remove the key which is not glued to the knob) and since the rotary switch needs a knob, there it was :). To be sure i used ca glue on the knob as well. For the moment there is no spring so the key turn back from the start position to the both position, I will maybe check later for a method to do that.