I have a set of used 2014 Subaru STI calipers that I am considering to have refinished. They're black and have STI logos, but they'll be going on a vehicle that is not an STI which is why I'm considering this.
Currently, they're fairly dirty and do appear to have some oil or brake fluid on them in a few spots. They also still have the original brake pads on them, as well as the other hardware except for the caliper mounting bolts.
Do I need to do anything to these calipers before sending them off to be refinished, most likely powder coated? If so, what?