Old thread, but I been busy...
OK, the vast majority of the SCW Mosins imported here had "Made In Russia" stamped on them somewhere. While it was pre 68 and the importers did not have to stamp a name on it, they were supposed to stamp country of manufacture on it, and mostly did. Perhaps this one got missed. I can absolutely see Russia dumping these on Spain and saving the trouble of modifying it. The Russians dumped all kinds of old, crappy, unserviceable or otherwise "nuisance" guns into Spain.
You got one with no stampings of any kind other than factory original...congratulate yourself. You just got a primo collectors' piece that a lot of people would pay a LOT of money for.
BTW, I think that it has a Polish M44? sling on it.