Hi Weatherby imported these a few years ago and they were made by Zabala Hermanos. The guns didn't last long as there were some quality issues that Weatherby had with them. In short they didn't want to have the Weatherby name on this import. The gun itself is one of Zabalas standard price point exports. The gun is an A&D action and was also imported by Charles Daly (Field Hunter II, not the Turk made 306), the Brittany series is common to these importers: American Arms, Tristar and BSA.
The differences included, engraving patterns, checkering patterns, type of stock grip. Some had sideplates (Royal and Sporting). But all had in common were SST, Choke tubes and ejectors.
While many consider these inferior SxS's they do fill a nich for a lower end SxS that can be used without worry. The main problems with these guns have been the ST and bbl regulation. You either get a good one or a crappy one. They also tend to be heavy for the gauge and the wood is rather plain.
I've owned/own Zabala's of this type off and on and to be fair they are not a bad gun, mine never gave me any problems and I have one I use for real crappy duck hunting weather.
You could do a lot worse.
Best!
Greg