I August 1939 the Home Office took steps to regulate helmet markings & colour. Helmets were to be painted black, & service markings applied in white, with letters 2" in height.
Luckily this one escaped, as it still has it's original factory khaki green paint.
The helmet belonged to Jean Adams, as seen by the name first in ink, then an cotton label stitched over it, which was made by CASH'S.
The white W to front & rear has been outlined in black.
The shell is dated 1939 & made by JSS, the Mk1 liner is dated 1938 & made by VERO.