Authentication of a Mies Van Der Rohe Barcelona Daybed  

Hi there,
I am wondering if anyone can assist me in identifying whether this daybed (see attached picture) is an authentic Mies Van Der Rohe daybed?
I bought it for a cheap price in order to offset the risk that it is a replica (which I am suspicious that it might be) . There are no tags or stickers on the frame or cushions. In addition, the frame is lacquered in black. All of the authentic daybeds I have seen have a walnut frame. Although knoll did a limited edition with a chrome frame. I am wondering if anyone knows if there was ever a limited knoll edition in the daybed that provided a black frame?
The person I bought it off stated that the stamping/authentication tags only commenced around 1960s and it is older than that. With that being said, I am wondering if anyone knows anything about the original mies van der rohe daybed pre-knoll issue - did this come in frames other than walnut i.e. black frame? Does anyone know what I should I be looking for to authenticate it?
I know that knoll acquired the rights in 1953 but what marks/authentication tags should I look for in an early production? I know that with later knoll editions there is a stamp in the leg but this only started in the 90s - if my memory serves me correct - and supposedly the daybed I have is circa 1960 edition. Any information would be much appreciated on how to solve/authenticate whether this is a real.
There isn't much on the daybed online. I found loads on the barcelona chair which hasn't been helpful.
Many thanks,
Anna