Bare brass, with nothing over it.
A living finish will oxidise and patina — it warms, deepens, and settles into the house it lives in. Two pieces from the same box will look different after five years in different rooms. That is not a flaw; it is the whole point.
Polished Brass starts bright and mellows, unless you polish it. Aged Brass arrives already dark and keeps going. Both are yours to leave alone or keep bright — and you are allowed to change your mind.