smle, the "Beretta importer" today is Beretta USA. But guns from the GR or 424 era would have been imported by previous importers. Beretta USA is a relatively recent creation.

The original Silver Hawks were basically 409's, "tweaked" a bit for the US market. Matter of fact, if you take the forearm off an early Silver Hawk, you'll find it's marked 409 in the wood.