Would anyone own a tonolini 8-bore double shotgun? They were imported by the old Navy Arms of NJ.I am looking to buy one,And would anyone know if the company still business?

The Greenhill Dictionary of Guns and Gunmakers by Walter and The Italian Gun by Smith & Morrow do not list this brand. You might try English Pinkiefootie-hunting Bros:
Wildfowling Magazine
There is an Englishman by name of Allan ? specializing in BB wildfowling thumpers.
The only other option is to get an oldie from 'specialist' firms like: Tolley, Bland,....