I found some references to Retolaza Hermanos (Brothers) in Eibar. The Eibar region of Spain is well known for the cottage firearms industry. Many, many copies of US and European firearms were made there for many years. The quality ranged from dangerous to pretty darn good. Have it checked by a competant gunsmith before firing and stick to light loads if it checks out OK.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball