Great Britain Bomber's Stop Watch from WWII

This stop watch seems in good shape for as old as it appears to be. There are a couple of minor flaws (minute numbers on the inside, slightly faded) on the face. There is a larger chip to the left and above the "55" mark. It still runs in great condition and always resets to "0." Any help with getting a ballpark figure with this watch would be greatly appreciated. Thanks

Fair