FYI, a common way to do color/paint inlays like this is to simply paint the whole piece, then carefully sand off the paint from the high points. What would be called 'lapping' most likely- put a grinding compound (such as sandpiper) on a flat surface, then rub the painted object across the flat surface.

So, if you removed the panels, and if they were flat or could be help flat by adhering to a flat plate of some sort.... and you could, say, hold fine sandpaper (1000-2000 flat to a palte of glass, say.... then carefully wet sand the plates....

Well, thought I'd mention a method. The problem with using polishes or such and trying to hit only the high spots is that hitting only the high spots is not easy!

Another method- double-stick fine sandpaper to a small block and use this to lap the metal faces. Wrapping a layer of thin clothe around a block and applying the smallest amount of metal polish is also a possibility. Make the block big enough to not dive into lower areas.

(Of course, not having one of these cameras to look at, I could be completely wrong about how they achieved the effect or what is possible to do to polish the metal.)