fantastic watch. You need to give us more details (ref number, photo) of your watch if you want more information.
However, here is a link to an article I ha written on the history of the Chronometre Royal watches and you may find what you are looking for in here : click here to read the article
a 4 digit number on the bottom of the case back. In any event to post a scan just click on the "+" icon and follow directions.
here's a pictural explanations on how to do so: click here to see the post