This helmet i have here, has been getting to me.
Ive always thought that this helmet was used in the australian navy.
Its a US m1 heat stamp 1128E high dome, rear seam. sand texture. the liner is firestone, sweat band DSA 69. with a grey over paint finnish.
The australian army and navy did use US m1 helmets in veitnam and early 70s. as far as know. the reason why i think that the australin navy painted there helmets black is that, I seen some images a long while ago but can not seen to finds them agiain. but i could be wrong. on all counts. cheers mark.