Upper wing halves cut out, sanded and glued together.
The early versions of the N.12 had windows in the upper wing center section to aid the pilot's view. The original kits had a clear plastic piece with the windows molded in, but I've long since managed to lose both of them. The new kit I bought didn't have it. After all these years they were probably yellowed anyway. This means I'm going to have to attempt to make it myself. We'll see how it goes.