Ah yes! "Gibson Girls". so named because of their slight resemblance to a group of young ladies called the "Gibson Girls", was a small radio transceiver box that had the crystals to transmit on the emergency frequencies. They were low power and placed in life boats and I believe that some of the life rafts that were included in some aircraft contained them also.
They were yellow and had indentations on the side so that you could place it between your knees (hence the "hourglass" figure). While between your knees you could hold it tightly and crank the handle which created power to run the tranceiver which would then automatically broadcast.
I am betting that if you do a web serach you will find photos of the "Gibson Girls" (female type) and a "Gibson Girl" (communications type).