How much is this vintage Omega 18ct gold watch worth?

Hello,
I am seriously debating wether or not to buy this Omega Genéve Crosshair Dial 18ct gold watch from 1968, and I can't really get my head around how much I should pay for it.

I really like the looks of it and the fact that it is gold. But it has a new crown and new glass becuase of prior service. It also has a mark on the case by 9'oclock, but the pictures won't really show it. It is 34 mm, and the ref. nr. is 131.019.

It is listed at $770.
How much is this watch worth? Is it worth the $770 from just the 18ct gold inside, or how much is it worth if not?

Thank you guys😀

Cases usually weigh around 10g

Not sure that's not a redial.

The Geneve script to me points to redial. Looks not original script. Correct me if I'm wrong.

All scripts look wrong to me, plus minute markers off at 12, 5, 10, ...

Never saw one and google only shows horrible redialed crosshairs.