help for hans wegner "the chair" (maybe!)  

Andrea,
 
Thanks for the additional pictures.  The joinery on the pictures looks legit to my eye.
I thought you might also be interested in the following article that appeared in the Christian Science Monitor in 1986.  It is an interesting piece on Wegner in its own right, but you will also be interested in the reference to Hans Wegner and Chase Manhattan Bank:
 
“Wegner's designs have always been made by the firm of Johannes Hansen, although he has sometimes designed for as many as eight different firms and had as many as 45 chair designs in production at one time. Some of his chairs have been in continuous production for decades and are in use in millions of homes, as well as hundreds of institutions, including Harvard University, the Chase Manhattan Bank, the United Nations, and UNESCO headquarters in Paris”.
http://www.csmonitor.com/1986/0620/hweg-f.html
Don't let all the skepticism detract from your enjoyment of the chair!

Wow! thanks Vivian and thanks everybody help me to learn new thinks about this chair!