British helmet or US,strange helmet info needed.

[Toecutter]

Had this helmet 25 years and never could find out what it is,very heavy sand textured finish,white diamond on side.any info appreciated.

[tinlid]

From my little knowledge of these, I'd say a WW1 British Mk1.

[Jerry B]

British made MkI, but many were used by the USA

[ppp p]

British made shell, but its liner looks like US made.
Any stamps under oilcloth?
Also camouflage paint is not British to me.
Anyway a very nice piece.
Piotrek

[Toecutter]

Thanks guys!Cant see any stamps under the liner,would anyone know what the white diamond is for?The paint looks original to me.