Yes, patina, but note that the term is misused in this context. Properly speaking, the first definition of patina is the coating of oxide that accumulates on copper or bronze over time and cannot be faked. It is something that accumulates on an object. By analogy, you could call the coating of dried lubricant that accumulates around some parts of a bike "patina," even though most of us would wash that away. The dull silvery look that aluminum gets, if it hasn't been anodized, is a true patina; and most of us put a lot of effort into getting rid of it. The second definition of patina is the overall look of an item that has seen a lot of use, including the signs of maintenance, etc, assuming it's attractive. When you're dealing with damaged paint, pitted chrome, peeling decals, it is something of a euphemism to call these 'patina.'