Speak Italian? This is all I could find other than some short references to good quality.
Francesco Pedretti
Via G. Pascoli 154
Gardone Val Trompia
25063 Bs Italy
Italy
Tel: 39308912339
Fax: 39308912339
And Numrich sells parts for some models.
John
P.S. - I found this Saddlery and Gun Room site from England that makes moderated(silenced) shotguns and uses a Pedretti as a base, among others.
"As with the .410 variety, the base gun is the classic, folding barrel 12 gauge Pedretti, which is almost unbustable and forms a good solid base from which to perform the conversion. If you like you can have your own shotguns converted and the supplier - The Saddlery and Gun Room also provide a moderator for semiautomatic shotguns. which I wilt test in a later issue. If that doesn’t tickle your fancy then a 9”, .410 unit can be fitted to the end of the barrel which works well but adds to a gun’s overall length."
I lost the URL, but a Google search on 'Pedretti shotgun' will find it.