barcelona chairs, very old  

a while back, I bought two barcelona chairs from a fella. at first I thought these were knockoffs and that was okay as I got a pretty good deal. upon examining them further, these chairs come apart in five pieces, they have the correct number straps, buckles, even the feet ends correspond to the very old ay of production. these chairs are extremely well made and no one would put this much work into a chair like that if it was meant to be just a knockoff for quick sale. the cushions are very heavy and natural rubber manufactured by pirelli and numbered.a crazy amount of work went into these cushions and they must weigh a good twelve pounds at least. now, the inside joint where the chairs join are numbered with a five. I contacted a group in europe and was informed that these sounded like one of the prototypes made up for this design. I know that trietel gratz made these chairs in america as well. this company worked with all the heavy weights, so I am inclined to think that these are some sort of prototype. the covers are pig skin. can anyone help with my research, this is quite interesting and fun to study. thanks