Set (8) of Balloon back dining chairs found at auction.

We found this set at auction some time ago. We have been researching balloon back chairs for some time but have yet to find a chair matching these. They have an extra "arm". The back of the chair comes forward a bit, creating a "mini arm", yet still extends down the back of the chair. They are covered in green velour, a plump full seat with tacking along the edge. On the underside there are springs, wide banding and twine, covered with a black mesh and tacked in with flathead nails. The legs are cabriole with slight carving on the top, bowed with a plain foot. The slight carving is on the center part of the ballon back and also on the upper portion. There are three bands of curved "tassles" on each side of the upper balloon back. It is not ornately carved as usual Victorian. We appreciate any information we can get on these beautiful chairs. We can't find one like it anywhere. When was it made, by whom? English, French or American? Help!! Thanks for your information and time in advance, we are still wondering.....................