Antique office Chair, Swivel tilt, adjustable back

I recently got an antique offcie chair. Metal hardware says "Milwaukee Chair Co. Patent Oct. 20, 1914. The chair swivels and tilts. Height is adjustable. The back is separately adjustable for height and depth. The really unique part is that the arms are attached only to the seat, not the back. The seat is upholsered and has springs inside. The back is also upholdetered. The upholstery currently on it is not original. The casters have been poorly replaced.  I am wondering if this is an original Milwaukee Chaitr Co. chair, or if it has been hobbled together from other chairs. I cannot find any pictures of a simialr chair online. Wood appears to be walnut. Any info would be much appreciated. Also, where can I go for information on the history of the chair? Thanks.