From Monte Burch. Gun Care and Repair. Winchester Press, 1978.
According to LeeRoy's Ramblings:
These guns were made by Angelo Zoli of Italy & sold to Weatherby. Not to be confused by his brother Antonio Zoli. Angelo has been out of business for MANY years & Antonio's guns, (sold under the Zoli name) were NOT the same. So NO spare parts are available, as the "factory" made these pretty much on order and had very few spare parts left even when the gun was discontinued.
These guns however, in reality were not all made by the same manufacturer. As it was a "Cottage Industry", in that MANY small independent gunsmiths participated in this venture. Some shops may have made the barrels, others the receivers, still others the wood &/or engraving. And who knows the assembly, with probably no one person or shop doing the complete gun.