I installed a Cane Creek 40 headset, as I thought the provided Neco was not good enough.
In the end, it doesn't matter. The bottom bearing is totally rusted after 7 months.
So Neco was probably as good.
From what I remember, the headtube of my 256 looked bare carbon too.
But may be if you scratch a little the surface, you will see some aluminium.
It did put the bearing/cup assembly in the headtube.
And had to press a little, to place the bottom part of the headset.