Nuovo Tipo hubs have the "winged wheel" logo on the hub barrel, while Record hubs have the Campagnolo script overlying a globe:
There are differences in the quick releases as well. The Record lever is retained by a nut, while the Nuovo Tipo lever uses a circlip. The Nuovo Tipo adjusting nut has a nylon insert to prevent loosening, while the Record adjusting nut uses a D-ring and brass inserts.