Most were made by Gamba
http://www.gunrunnerauctions.com/listings/details/index.cfm?itemnum=981428634They shoot well enough
I have an original stock and forend sitting around here somewhere.
Another posted
"I owned two of the single barrel "Trap Grade" Mauser's a few years back, model 496 and model 496 competition. After writing to Germany's Mauser-Werke Oberndorf, they informed me the replacement parts I needed would have to come from Renato Gamba of Brescia, Italy. I did write to and buy my parts for these shotguns from Renato Gamba.
Societa Bresciane S.r.l.
Messrs. Renato Gamba
Casella Postale 124
ViaArtigiani, 91
I-25063 Gardone V.T. (Brescia)
This address is ten years old."
Mike