I took the front panel off the mystery machine today in order to take some better pics. It's beautifully made. Take a look at how the wires have been neatly tied. This is an array of resistors at the centre of the machine. Other parts seem to be a transformer, a rectifier, two rotary stepper switches, a row of what Dad informs me are GPO relays and some LEDs. Kind of a mishmash of technologies but not a transistor or an IC to be seen.