I had a request for a Viking helmet with a detachable beard. I got Rob to try it on so I could attach the sides of the beard in the right place:
Verdict: “warm, cosy and very very stylish. Especially if you’re a Viking”.
Incidentally, Vikings didn’t ever have horns on their helmets! According to wikipedia, this concept was an invention of 19th-century Romanticism, when Carl Doepler created horned helmets for the first Bayreuth Festival production of Wagner’s Der Ring des Nibelungen in 1876.