Duck- welcome to the forums- when you get a minute, stop by the intro thread and say howdy.
Your revolver is likely from a section of Spain (Eibar) that was home to dozens of small companies that made copies of Colt, S&W, and Browning handguns. Ever notice that S&W has "Marcas Registrada" stamped on it? That's why!
We REALLY need some pictures. A close spelling of one of the makers there was Arizmendi, Zulaica y Cia.
Quality varied from so-so to not bad. It MAY be a .38 S&W, may be a .38 Special. If not marked with the caliber, you need a smith to check it over.
Values? Not real high, depends on condition. Got pics?