If you have the patience to work with foil most anything is possible. I don't personally. Doing the trim on a car is enough for me. Some people have a knack for it though. Valve covers would be easy enough and some other parts.
You can use Testors Dullcote on chrome to take away some shine or make it look more like aluminum. I usually strip the chrome and use different shades of Alclad and Metalizers to get the type of finish I want. That way you can clean up any flash or mold lines on the part(s).
I airbrush just about everything. I also prime everything. Then shoot a black basecoat on anything that will have Alclad or Metalizers used on it. Do all your fitting beforehand and you shouldn't have to handle anything too much during assembly to rub the paint off. Basecoats aren't necessary for Metalizers, that's just the way I do it, but does help sometimes.
These are the paints I have experience with, others are available.
Tony