Yes, at least back in the '70s the Gran Sport hub was also known as Nuovo Tipo (new type) and is as you describe for the low flange: no spring clip covering oil hole, different logo engraved on shaft of body, and different QR end (round with knurling, no D-ring) lower polish/degree of finish.
AFAIK, the internal parts are all interchangeable with Record of the same era, and again the only difference might be the fine tolerances given the bearing surfaces, but I'm sure I've used Gran Sport cones in NR and SR hubs will no ill affects.