Imperial Coffee Mill

This is an antique coffee mill that my father claims that has been in my family for 4 or 5 generations. It is missing a piece of the base in back and as far as I can tell it is the only piece missing however I could be wrong. I've tried to search for it all over and I've come close to what I have but not exactly I'm hoping that you all can help identify the acurate model I have and of course its worth not because I want to sell it but because I believe that it will be an interesting anacdote for my future family to enjoy. Its' been in my family for a while and I would like to keep it that way.