I found the text "The first and only watch worn on the moon" on a sign attached at the moon lander display used in stores, on a display stand that is attached to the watches and on a caseback.

The text was changed to "The first watch worn on the moon" later.

When did Omega change the text? When were the signs used as dealer displays? Is it possible to date the items because of the text?

Here are the found items:

 

Nobody?

 

The sapphire "First and only..." display case back's were produced from 2002 - 2016. So probably around then.

 

I believe “the first and only” is very recent production with the new caseback. I believe it’s also a niad system caseback. Or similar like the starmus that makes sure the caseback is aligned.