Antique chair needs a name_era

I LOVE this chair but don't know it's age or style. I would love to know history style of this chair. I discovered a mark stamped into the backside of the wood skirt it is either a T57 or 157 (see close up photo) The paint is orig/ oak wood. The chair sits low. leg is 7.5" to front of wood skirt, is wide and the back is 40" high. It was upholstered 8 years ago so I can't see the joints. I can feel the webbing and coils through a hole underneath... . The scrolls are simple folksy carvings. The front legs are turned but the back ones are not. I have no idea of style, age or value. It was my mother's purchase years ago and she was a big antique hunter It was scheduled to go in her estate sale but I couldn't let it go...so I have brought it home with me to keep and enjoy.