Omega De Ville Automatic vintage watch, information/authentication help

I would like to have some information about watch that I have. I know nothing about it and would like to know is it genuine Omega and what is the specific model of it. Haven't found any similar anywhere. And also would like to know value of it and if there is interest for buyers anywhere for that kind of watch.

Movement works and didn't have that bad beat error or +- rate for being not serviced in years probably.

Here is pictures.

Have you any idea what kind of price Im supposed to ask if I will try to sell it?