Is this Brazilian Rosewood? Arne Norell Sirocco safari chair  

Neither the woods are
Brazilian rosewood.
The first image is african wenge
The second is indonesian rosewood used after the brazilian was banned in 1978

I really appreciate the quick response.
Wenge makes sense.
Most of the Arne Norell chairs on 1stdibs list the chairs as being Brazilian Rosewood none say Wenge, which is why I posted the question. But the guy at my local lumber yard thought it was Wenge too.
And does the chair being Wenge say anything about the chair (age, manufacturer, knockoff)?
Here are some photos of my chair.
Thanks again.

SCANFORM?
I had one of these chairs. It turned out to be made by a South American company called SCANFORM. It seams they may have been licensed to produce these chairs ? so not sure if they count as knock-offs? SCANFORM was also known to use all kinds of exotic woods. If SCANFORM, there should be a tag or remnants of a tag on the underside of the cushion.
http://www.scanform.com.co/contenido/historiaing.htm

It's impossible to definitively ID the species
without sending a sample to a wood technologist for microscopic analysis. Even then, the result may be less than conclusive.
That said, it does seem to resemble Wenge, but so do many other tropical and subtropical species from regions outside of Africa. You might send your photos to various exotic lumber dealers, many of whom maintain good websites, for some help finding a good match.
What's fortunate is that the missing rail is one of the least obvious components of your chair.

thanks for all the responses
I think I am going make the replacement piece out of Wenge and hopefully it will not be easily distinguishable as the replacement. Plus I could switch it with the existing piece just below that is mostly covered by leather.