The overall thickness is consistent with the bullet resistant glass made by the British. I can't find details of the construction (I have them somewhere), but it sounds about right.
As for the aircraft, I think the shape is wrong for the suggested Hurricane, on which there was more of a taper towards the top. The sides on yours look almost parallel. It is the right sort of size for an 'armoured' windscreen on something.
Glass like that was produced for a long time after the war too.
Cheers
Steve