The difference is in the shock protection for the balance wheel. In the one you posted, the shock spring is "clover leaf" shaped. I believe that is a peculiar design to the Kif company, Mine has the more "usual" waisted shaped spring that was the original Inca design that they patented as the Incabloc (well actually the whole assembly rather than just the spring). In fact the company is now called Incabloc and if you click on the "Products" tab on this web site:
http://www.incabloc.ch/incabloc_en.html
you will see a very good exploded view of how it works.
Generally, the Kif springs are now similarly shaped to the Incabloc ones:
http://www.kif-parechoc.ch/old/en/en_horlogerie.htmClick to expand...