Pocket watch

My uncle gave me this plain pocket watch years ago. We believe that it may belonged to my great-grandfather Pablo, for the P engraved on it (you also see a P?). As you see in the picture, several parts are missing, including the clockwise. A jeweler told us that could have a hundred years. I did not find any significant mark, just says it was made in Swise. On the inside cover is engraved "cylindre remontoir", and inside of both outer covers only the numbers 0800 (0800 silver, I suppose) and 41519, "Argent dore" and I do not know what the other brand is , look like a C flat. If you know something more, like the date, I'll be grateful. Thanks!