Florence Knoll Settee Authentification  

Hi all! New to the forum, first time poster.
I recently purchased a sofa hoping it would be a Florence Knoll Settee, but since there are no labels/maker's sticker I can't be 100% sure. Not sure if it is Knoll, Steelcase, or another replica.
Here is a link to an album with several pictures: http://imgur.com/a/qOPnL
Here are some of the attributes:
-Four removable cushions.
-Not tufted (possibly cheaply re-upholsterd by a previous owner).
-Two back cushions have a wood insert for stability as seen in a picture in the album.
-Segmented legs that seem solid and not hollow.
-Sloped wood frame that slopes downward towards the back as seen in a picture in the album.
-Back and armrest are all same height.
-Has springs, possibly the Knoll no-sag springs?
Any help in authenticating would be appreciated. Looking to find pictures of the underside and how the legs join the frame in other authentic knoll sofas.
Thanks!