In-game; Armun-An Bonemold Armor is favored by House Hlaalu while Gah-Julan Bonemold Armor is favored by House Redoran.
Telvanni on the other hand uses the Armun-An chest and shoulders, but wear their Cephalopod helms instead of a traditional Bonemold helm.
My question is: where does the Native Chuzei Bonemold helm fit into the equation? I've only ever found one in game, and it was owned by one of the Telvanni mercenaries outside Tel Branora that you kill for a quest. My guess is that it may have been the variant used by house Telvanni before they adopted the Cephalopod helms. This is all wild speculation, the only things that lead me to believe this this are:
1) The other two Great Houses have their own unique Bonemold helm, Telvanni does not
2) The general shape of the Chuzei helm kind of resembles the same style as the Cephalopod helms
3) The one in game I found was looted off a Telvanni retainer
Of course it could very well belong to House Dres, Daggoth, or whatever. I really have no idea. Can anyone satisfy my curiosity?