Need help to ID an Omega pocket watch movement.

Some might remember the thread I posted about an Omega pocket watch under 1 million.
I just bought an other Omega pocket watch which is close to 1 million and something is baffling me,the movement is the mirror image of a caliber 19. I've never seen one before,is there something I'm missing. I searched in The book and I haven't been enlighten. The main difference is in the pallet bridge. Hope this question isn't to obvious and makes a fool of me.

My research led me to this:
http://omegaforums.net/threads/opinions-welcome-on-this-19-lignes-caliber.9357/
Thanks for the answers to my questions.