Omega De Ville - What do I have here?

Hey gents, was hoping one of the experts here could take a minute and lend some of their knowledge. I'm waiting for a watch case opener to arrive, but based on what I've seen here on other identification requests, this piece is probably old hat for y'all.

I picked up this piece on a whim from a seller here in Tokyo. There wasn't much information but it runs, albeit slowly. I'm sure it would definitely cost more to service than the purchase price, it would be nice to know either way what I have on my hands and if a service makes sense.

Many thanks!