British Turtle Helmet dated 1952.
In great condition looks like the foam block inside centre of the helmet has seen some heat, as it is melted. Other than that, it seems pretty good. Needs a good clean inside.

It is Marked 7 FFL III 1952. 

Similar helmet to the 1944 used on DDay and onwards throughout the 50’s and 60’s

The photo's as they form part of the description.