Aha! Thanks for the responses. I was afraid it was an npc only helmet.
Hehe, I have characters wearing both the splint armor set and the vigil armor set. I am a big fan of the simpler more historical themed armor sets so when I saw Warmaster Grast's helmet I was hoping it was another helmet to add to my collection.
But alas! It doesn't seem possible.
Maybe if enough of us express an interest ANET will add it in the future? 😋
One can always dream right? 😜