Help on identifying vintage Omega watch

Hello,

First post 😀 I am quite new to the hobby of vintage watches.

I have aquired this watch, but I am not sure if it is legit, and if it is, how original it would be. I am new to vintage watches, this watch cought my eye because of the patina (I quite like the looks). I am not so sure about the indexes, could these be original?

what is your opinion on this one? Thanks!

The reference is on the inner caseback: 2540-2. And the calibre: 265. The dial does look strange to me as well but the pictures aren't in good enough lighting and high enough resolution. And I believe this reference came with leaf, dauphine, and sword hands. This one looks to have unlumed pencil hands which are quite unusual for an Omega. Not to mention the 'coloring?' on the 12, 3, and 9 indices - likely added for visibility. Seconds hand is correct. And the crown looks original but I can't be sure about that.