Don't know what is currently available but in the past when I needed a similar product I looked to the big rigs. They often have a lot of aluminum work on their rigs and always seem to have a ton of products for protecting those surfaces. Some others might suggest military, for polished surfaces on ships though there are allot of hands available to keep those shinny or air craft
Sorry don't have a particular current favorite. Maybe someone else will
You might also consider a good wax or ceramic coat to protect these though I never had a problem with the surfaces on those valves considering how the cars are currently maintained and stored