Help identifying these rare Omega De Ville's

Hi and welcome.
These are typical 1970s watches from a time in Omegas history that many would like to forget and unfortunately rare does not necessarily mean desirable. The movement number you have shown may date from the late 60s but it is not unusual that they could sit around in the factory before being cased and these watches both have a 70s feel to me
One or both could be 18k gold but without seeing hallmarks or casebacks I would just be guessing.

More information regarding movement calibres and model reference would be available inside the caseback and on the movement.

Finally see this omega page for similar-ish model I found by searching omega ba351

https://www.omegawatches.com/watch-omega-de-ville-omega-ba-351-8383