Acrylic lacquering practises

I have been thinking what I should do with the copper surface, what kind of finish I should aim for. 

Copper oxidises naturally, depending of the environment, it darkens, patina, over the time. I am between letting the copper on its natural stage after polishing or lacquering it with acrylic - which would prevent it from oxidising and it would stay patina-free. Also, the acrylic would protect the metal from getting scratched.

I went to my helpful friend Carl's house, who has an airbrushing studio. I had test samples, with different kinds of finishes on them. 

Here's some of the samples. Two half domes, the other one highly polished, and the other naturally oxidised one. The disc has been roughly scratched and the rectangular piece was polished with metal wheel.  The test pieces have one layer of acrylic lacquer airbrushed on.

This rim is in three differently polished sections - linear sand polish surface, two different grades and one part has been left to oxidise for about a month. After lacquering the surface, the metal will stay in that colour, which I find fascinating. But what I am not so keen about is the shiny surface, film that the spraying creates. It can be seen clearly - it looks artificial to me.

Being true to the material. The material should celebrate the medium it is made of.