On the top one with wire brush the threaded area (looks like it already has been and oil
On the bottom pictures I would
Red arrows - Brighten by passing a very fine sand paper over the surface. Could use it in a band form - might make it easier
And leave the other surfaces the cast color - Did look for any pictures of the ones I've done recently but hard to get the details in a picture. Either its too dark to show the differences our too bright and the reflections produce an odd look - or even hide the differences between the finishes