there is a difference between the state of the dial and the oxidized hands. it doesn't make sense to have a "clean" dial with hands that have suffered from humidity.
when something is not normal, you have to look for the other elements. there it's easy seeing the back of the watch, we've never seen that at Omega, it's too coarse.
anyway, post the pictures here before buying, there will always be someone to help you. over time, your eyes will get used to detecting fakes. do not hesitate to participate in other conversations, it helps a lot!