Spitfire spade grip ?

Hi Everyone,

When me grandfather passed away years ago, I received an object (I was told from his Spitfire plane that he managed to land/crash in unpopulated area after an engine malfunction.
Was told he even received some kind of medal for this.

Below picture of the spade grip. On the shooting button I can read the number (aho 16041)

http://imgur.com/a/lVlCi

Does anyone know from which type spitfire this is ? Are these things beeing collected/valuable ?

Thanks
Tomas