For the specular highlights, you can help them by making them less shiny. Look for a spray product called "dulling spray". Krylon made some, but if I recall correctly Blair made a better one. Art or photography supply vendors will have it. It is reasonably easy to remove. If the art is not your own, obviously you should ask the artist first. This art looks like it would clean up OK.
One way to think about reflective objects is as if they are a mirror and that they see the light you put them under and reflect it. Curved shiny things make it harder, like a funhouse mirror might. But part of the curved shiny thing is that it also gives nice modeling so that the object reproduces as more 3D looking rather than flat. Its good and bad. You just have to control the bad by making choices about how it shows.
A really big light source will help. One way to get this if you don't own a big lightbox is to use a big flat reflector as the light source, bouncing the light you supply onto the object. So, one or more fresnel spots located out of the frame and aimed at the big reflector will give the effect of one huge light as the light bounces off the big flat. Get the big flat real close to the object and it will appear to be bigger in effect. Imagine the light bounced off a sky that is filled with white fluffy clouds - all enveloping and even. The opposite would be direct sun which is huge but it will make tiny specular highlights bouncing off objects because its really far away. You can even choose the shape of the refelctions by choosing the shape of the light source. Want long skinny reflections? Use a long skinny light source. Remember, the object is a mirror and your camera will see the reflections off the mirror.
Give the capture plenty of exposure. You can do that a little better now with dulling spray on the shiny metal. It won't be so reflective and less likely to make the sensor bloom or be out of the sensor's dynamic range. Once you get enough exposure on the object for all the detail you want to show to be lit, you can kill anything on the proper black background with curves or levels in PS or your camera settings. It is sometimes easier to shoot it right though so think about how to eliminate the background from reflecting any light back at the camera.
A good background would be black duvetene fabric. Check the big photo houses for that. Or here - http://www.filmtools.com/duv54rolx50y.html (don't know them just first thing that came up and they have dulling spray - http://www.filmtools.com/krylon-dulling-spray.html) And yes more separation from the background. You can even hang the object with fishing line if its too hard to get what you need otherwise. Hanging the object mid air in front of a black cave will absolutely do the trick.