Fake. The "Officine Panerai" engraving on the movement is WAY too big and bold. Also, the needle regulator is a dead give-away. :wink:
He doesn't ever claim it is authentic Panerai, though. "100% Genuine ETA Unitas", doesn't mean 100% genuine Panerai. That seller is obviously skirting the boundaries of false advertising, these are deliberate word games to intimate that this is real Panerai without actually saying it outright.