Looks like (1) a poor quality of anti-corrosion coating on the metal at the factory, and possibly (2) a lack of proper application of any anti-corrosion oil or grease at the armory or warehouse when they were put into long term storage (like cosmoline or any modern equivalent of it). But that's just a guess from the photos.
Might require some buffing out of it, and then a re-treatment of the metal to keep the rust at bay.
I am STILL waiting for any status update on mine.
Waiting for RCMP transfer approval.