And for those of you who are wondering just what the hell we're babbling about... The Spanish Civil War was fought just prior to WW2 (1936-1939). In addition to various Spanish Mausers that were stockpiled in Spain's arsenals, both sides in the civil war used a wide variety of whatever other rifles they could get their hands on, usually provided by foreign countries who sympathized with their side. The Right-Wing/Fascist Nationalists received most of their aid from Italy and Germany. The Left-Wing/Communist Republicans received most of their aid from the Soviet Union, Mexico, and Poland. So there were plenty of rifles from various sources in circulation during the war, including Spanish Mausers, Soviet Mosin-Nagants, Polish Mausers, Czech Mausers, German Mausers, Mexican Mausers, French Berthiers and Lebels, former Austro-Hungarian Mannlicher rifles, and a number of others.
These various SCW rifles were collected up by the Nationalists after they won the civil war, and they later sold a number of their unneeded rifles on the US surplus firearm market In the 1950s and 1960s, Most of these SCW rifles don't have import marks, or have non-standard import marks, because they were imported prior to the 1968 Gun Control Act that standardized import markings. And many of them will have noticeable signs of Republican or Nationalist Spanish use.