Thanks for posting and welcome. I think JimH might be able to help with Eterna serial numbers.
Usually if you post a picture of the dial case and (hopefully) movement we can do better with ID.
Values we don't do here. Please read our sticky notes for reasons why.
@ Jim HHi,
don't worry about different numbers on case and movement. Cases were
produced in about the same quantities like movements. But since there was
always a great variety of case models, they were produced in batches on
stock, and by average earlier than the movements. So the case is almost
always older than the movement, and therefore has a lower number than the
Regards, Roland Ranfft