Barcelona Daybed Help !?  

design addicts,
I am in a conundrum. I have found a vintage barcelona daybed available locally that I need help authenticating. This is most likely a case of too good to be true (esp. with regards to the price vs. market) but before I walk away I will break down the pros and cons as far as authentication and ask see what you guys/gals think.
Pros (it's real, grab it):
1)Knoll, Int. sticker on underside of cushion. This listed the customer as well which happened to be a Federal Building that I have forgotten the name of. The sticker is very similar to this:
Cons (Run away):
1)According to the seller, the dimensions are 36"x72"x16". Stupidly I forgot to bring my tape measure to confirm the if dimensions listed are inaccurate or if the piece really is smaller than the typical, 39"x78"
2)The curved crossbars are black, not stainless. They also appear to arc more than the recent ones, as shown on DWR's site.
3)The legs base plate was round, not square or rectangular, as also shown on DWR's images and various vintage listings that I have been able to find.
Given that this piece has been in production for years and probably via several different places of manufacturer for Knoll, I expect that there might be some variations in the details of the piece, but I'd like to know from those with experience if they have encountered anything as described.
Normally I'd say it's a reproduction, but given that it seems to be a vintage piece which I would equate with a time not filled with reproductions, and THE KNOLL STICKER, I am giving this piece the benefit of the doubt for the time being.
Thanks for any and all help you might be able to provide.