Manufactured by Forbes and Lomax.
The Unlacquered Brass range has brass plates that are designed to mellow with age if left unpolished. This is particularly suitable for period buildings where a bright brass would look inappropriate. Alternatively, the plates can easily be polished to give a shiny look should this be required. Read more about the formats available, the features and the models(with pictures) of this finish(unlacquered brass) from Forbes and Lomax.