Has anyone heard of a "SIRIUS 15 Rubis" pocket watch?

I have an old pocket watch which says SIRIUS as the brand and 15 rubis underneath. Behind the back cover there are engravings of a buffalo, a moon next to a crown, a box which has the number 0.813, and a number by itself 3151 underneath. I was unable to find any information on a watch like this. Any idea of when it was made? what the markings on the back mean? and/or approximately how much its worth?