Update: the only place with actual WOOL felt dressage girth was Whinny Widgets. Kitty was very helpful, responded to my questions promptly. She custom makes each girth, so you can choose if you want elastic on both sides, not at all, etc.
Mare & I are very pleased with the girth. It is well made and the felt really is great for wicking, esp with her winter fuzziness. It cleans up easily with a stiff brush. I was also happy that the price was more than reasonable. You can get in brown, black or custom color.