Attached are a couple of snaps taken after an afternoon of sun in the sun. Anyone been successful at getting the unpolished metal bits (torque brackets, etc), cleaned up without removing them - a job I wouldn't take lightly, either.

The plastic, vynil and rubber parts are relatively straightforward - it is the metal I'm interested in keeping corrosion-free, once it has been detailed out.

Any protective coat of anything that might be applied to them?

Yes there is a protective coating.

Its called Meguiars Hyperdressing and it both dresses the engine REAL nice and protects it from dust/dirt. I assume you mean for the engine and not specifically the metal parts right?

For the metal parts use Meguiars NXT All Metal Polysh. Works great!!! And to keep them nice and clean go ahead and use some wax on them. It works great because the dirt/dust cant really stick to the metal, and itll be much easier to clean the next time around.