I would love to see pictures/description on how the electric circuit is done!
Today this is easily achieved with the use of a MOSFET (or simular) switch, or a more fancy solution where the hands capacitance lags an electric pulse enough to trigger the switch.
But how this was done in the 30's, is interesting.. Wikipedia tells me;
'In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor. There is no direct evidence that these devices were built....'
The mass produced bipolar junction transistor didn't come until a while after the war. So if that thingy has some sort of transistor in it, that would VERY interesting! But highly unlikely if it's from the 30's..
There are ways to make this sort of connection without the use of transistors or 'chips', but as an electric power-engineer (I'm not that much into electronic's), I just can't see a good reliable way to do it. I will give it some more thought when I find the time to do so.. perhaps they had some metal threads in their gloves that made a sufficient connection without the use of switches, but gloves would be kinda silly with a Luger..
Thoughts would be appreciated
Interesting piece!