I recently found my fathers Rolex in a box of his things.  Serial # says it was made in the 1940s. He bought it in the 1960s I believe.  It's an Oyster bubbleback with the California dial.  UNfortunately the dial does not say Swiss Made so it is believed that it has been replaced but if so it was a long time ago from the looks. The rest of the watch is original.  I really like the art deco look of the dial.