RAF Morse Key

Many years ago I picked this morse key up at a junk sale - I imagine I paid very little for it as I was never seriously into morse code.  I dabbled trying to learn for a while, then forgot about it.

As I've been getting interested in radio again I dug it out, and I thought I'd look up the reference number to see if I could find out anything about it.  It's a lot more interesting than I realised!

"This was the standard key used in British (and Canadian) bombers such as the Lancaster, Halifax and Wellington aircraft during WWII. It is enclosed for use in explosive environments. All of the parts are brown Bakelite. The wire terminals are on top, and the adjustments are inside. The clip holds the cover closed, and can also be slipped over the skirt of the knob to hold it down and so send out a continuous signal. This allowed the radio operator to parachute out of a damaged plane while still sending a homing signal for rescue craft."

I have no idea what the history of this one is.  Did it fly in a bomber in World War 2?  Was it used for training, or just surplus stock disposed of after the war.  I suppose I'll never know.