Rulings

Each time the ability triggers, you can pay only one time to get one token.
As the token is created, it checks the printed values of the artifact it's copying, as well as any copy effects that have been applied to it.
The copiable values of the token's characteristics are the same as the copiable values of the characteristics of the artifact it's copying.
If the artifact that caused Mirrorworks's ability to trigger has already left the battlefield by the time the ability resolves, you can still pay . If you do, you'll still put a token onto the battlefield. That token has the copiable values of the characteristics of that nontoken artifact as it last existed on the battlefield.