Hi,
I'm at the end of my very limited expertise on Sennah pile rugs. However, I did stumble on this article by Marla Mallet, who seems to know more about weaving than anybody.
http://marlamallett.com/up-three.htm Look for the section titled "A Distinctive Senneh Weave." What she describes is a sort of hybrid single-weft weave, not like a Bijar at all.
As for single vs. double wefted, I have also seen referenced to single wefted Sennehs, but generally see them called double-wefted "like a Bijar." Here's an explanation from Barry Connell:
From: Susane
Could you please tell me what is a Seneh rug and what does it look like?
Thank you,
Susane
Hi Susane,
Three main types of rugs are called Senna, Sennah, Sanandaj, Bijar, Gerus Bijar etc.... There are Sennah kelims which are finely woven wool flatweaves these are rigs with no pile. Then there are thin city rugs. I have never seen a new one. They are easy to spot because they use traditional patterns but are single wefted and are thin and fine. The new ones are made in the surrounding area and are thick and sturdy with a deeply depressed double thick foundation. I went through my notes and found a few examples.
Senneh/Sanandaj Rugs the O'Connell
Best wishes,
Barry
So, "deeply depressed double thick foundation" is quite different than what Marla describes. Confusing! Still, the back of your rug did not look like Marla's description, and it did look single wefted, so I would stick with Hamadan until someone opines who knows what they're talking about.