[Regia-NA] Wanting feedback on a helm

[Wil Y]

Greetings all

I'm trading an armourer in Texas a maille shirt I've been working on for a
helmet. My portrayal is in Hedeby, in the year 805, and as I'm sure you know
there are no helm finds dating to that time period and locale. The Danes
fought quite a bit against the Franks in the last years of Charlemagne's
life though, so I thought I would look for an appropriate helm in
Carolingian sources.

http://home.armourarchive.org/members/brodir/GoldenPsalter.jpg

I've decided on this helm, it's from the Golden Psalter of St. Gallen, which
is Frankish and dated to about 860. It's basically a four-panelled
spangenhelm, round topped and fairly deep, with the nasal integral to the
browband and flared away from the face just a little at the bottom. He's
making it for me entirely out of 16 gauge mild steel, with round-headed mild
steel rivets. I've asked him to attach the four bands to a central hub on
the top rather than just overlapping them, and I'm sort of flirting with the
idea of an oil-blackened finish.

Opinions? Is the central hub construction OK authenticity-wise? Oil
blackened finish acceptable? It comes out a dark, iron color, not glossy
black or looking like paint. Anything I need to tell him about rivet
spacing? (Some fighting groups have standards about how close rivets have to
be to each other, to maintain the structural integrity of the armour) What
is the policy on brass rivets?

Thanks greatly in advance, I appreciate the feedback from the members here!

~Wil