It looks like one of these older british copies. Easy to spot on a side view: the shell is higher than normal for a circa 1914 helmet. Would you have such a picture?
Besides, the rims, liner, spike are the same as on these fakes, which often come in black colour.
I agree with Bruno on this. It looks not original, this is a helmet I had before,
As you can see, the rim is not so thick, the example you show here, looks more like a copy of a Von der Heiden kit helmet. Also, it does not have the ridge were the Von der Heiden kit helmets had the front and rear visors attached to the helmet. As it is a one piece helmet, it should not have that ridge.