Crikey! No kids.
That last one that Lucky posted was very evocative; it shows a Lancaster flight engineer and with the help of a copy of the Lancaster I Pilot's Notes, the switch he's got his finger on is the fuel contents gauge switch. When this is depressed, the needle on the gauges swing to the level in the tanks when the aircraft is static. I thought it might have been a Manchester since the cockpit layout was the same, but you can see four each of fuel gauges and power and condition levers between the flight engineer and pilot's seat.