To polish or not to polish? That is the question.  

Yes, it looks great --
and I agree that patina has little to do with the value of this kind of object. Rather, it should be kept looking new, if possible.
Tktoo makes an important point about plated finishes; it is all too easy to remove a layer of material without meaning to, exposing the base material or another layer of plating. It looks like this lamp was composed of solid brass parts -- or else the new owner chose the right methods and materials for his (surprisingly rapid) restoration !

I'm pretty sure that it's...
I'm pretty sure that it's solid brass rather than a finish. I think if the quality
Is there to start with it makes a big difference to the result. I had a similar situation with a pair of 1950's wall sconces I bought recently which had their base plates painted black. There were some scratches and I could see the brass underneath. The paint washed off in hot water and revealed solid brass which shined up nicely.
I think the quality and attention to detail in the design of some of these lamps is quite incredible. I can't imagine there will be many design objects from the noughties kicking about in 70 years time.
Cheers,
Tick 🙂