A standard Mk2 No.1 military issue helmet belonging to F/O Parme'e, & what I can see of his service No.3318-8, but that's probably wrong.
As you can see his number & name are written on the outside brim, the yellow paint on the top of the helmet I'm pretty sure is gas detecting paint which is extremely rare to find.
The shell is dated 1939 & made by RO&Co, but the Mk2 chin strap lug is dated 1938. The liner is also dated 39 but made by HELMETS Ltd.
The chin strap also has his name on, F/O PARME'E, British, French, French Canadian, or Belgium?