Polish, finish appropriate for the 14th century

We have only a few examples of how armour was finished during this period. Generally, it appears as a satin brushed finish, something you might achieve with thousand-grit sandpaper. Other sources speak of highly polished armour, "that glints in the sun." Still other armour was painted . The reason for this polish is that it resists rust , and that it imparts a glory to the pieces rarely seen in the modern world. It evokes the image of the "knight in shining armour," connecting the combatant with the romantic history that feeds tournament reenactments.
To achieve this finish now, a belt sander with a 2" x 72" belt is the best thing I have seen, followed with a polishing wheel of 80 grit to a high stainless polish.