Is this helmet real?

[Sextus Saturninus]

I saw this helmet and I thought immediately that it was fake because it has a riveted on neckguard. I remember learning that Roman helmets were raised from one piece including neckguard always. Am I wrong? Is this a real helmet and were the neckguards riveted on sometimes, or is this just a fake?

Thanks for your replies in advance. Here is the helmet: