Selig Jensen Z chair wood options  

Hi, while looking around for 1 or 2 Selig Jensen Z chairs over the past six months, I have come across the following wood options: teak, walnut, and stained beech. I have only had the chance to see a couple firsthand. However based on those examinations as well as many photos online, it appears to me that many of the teak and walnut options still have stained beech for the seat frame and back rest spindles. The teak or walnut appears to me to be limited to the side Z frames and the crossing members.

My questions are: 1) Do all teak and walnut options have stained beech components, or are there some all-teak and all-walnut versions out there?, and 2) Am I way off base with my observations and the original chairs always use the same wood throughout? Thanks.