Illums Bolighus marked dining chairs  

@frankielemmons. Henry Rosengren Hansen; Brande Møbelfabrik ( Møbelindustri); Model 39. 1960.

@lexi many thanks! Your catalogic knowledge is amazing.

If you do an image search it is interesting to note that the chair was also produced with the centre part of the backrest upholstered. This could explain some of the colour difference 🤔 Hansen produced chairs in teak and rosewood.

@lexi indeed. I was assuming the color difference was largely due to the end pieces being end grain, while the middle part is face grain. I can't imagine such nice wood being used in the upholstered versions. I am pretty confident these are rosewood now.

Also, I noticed that some examples have side stretchers and other do not. 

These are definitely rosewood. No doubt about that.

However, I'm not convinced the backrests aren't veneer.

@kyle-barrett they must be veneer, why else would there be the thick edges on top and bottom of the backrest?

This is a close up I found online.