Pewter (or chrome?) Floor Lamp

I traded a bit of labour for this 1940s (?) floor lamp. I thought it was made of brass (or brass-plated) because it was quite amber/yellow when I saw it - and since I like brass stuff that's also why I wanted to buy (trade for) it.

Imagine my surprise when I started cleaning it and ended up with what's seen in the photos! Turns out the previous owners were chain smokers and 60+ years of cigarette smoke had taken its toll. Fortunately it cleaned up to the brilliant finish it has now and the glass shade is to die for!

I'm not sure if it's chrome or pewter. The main post is magnetic but the base and lamp housing is non-magnetic. Seems to me that pewter would be non-magnetic and chrome would be magnetic. Perhaps someone could help me out on that subject?