Kagan coffee table real or knock off  

So I have this walnut coffee table. I found many auction results, some exactly the same as mine and others with two notable differences. First, mine has a center piece that the three legs connect to. On the Kagan site the three legs appear to just joint together, like a few other examples. Second, the legs on mine curve down, but the one on the Kagan site doesn't. I have also found examples without the center pieces, just the three legs joining together but with curved feet. Has this design evolved over time or are all of those auction results fakes? Mine also has a hard to see signature or inspection markings on the underside.