Givenchy Watch

Vintage wrist watch in need of a lot of cleanup/refurbishment. The color is worn off, otherwise the watch works fine. I stopped replacing the batteries because no one uses it anymore. I've had this watch for about 20 years and it was already vintage at the time I got it. It used to be my grandparents', and there was a case and certificate with it, so I'm 100% sure it's authentic, but we've moved so much and I think the box was misplaced/I can't find it anymore. Please ask me any questions and I'll try my best to answer.