Howdy Dwayne, the reason I say Czech conversion was the proof mark and SN. These are Czech, thus John's notion that this was sporterized on this side of the pond seems unlikely. Brno converted many a surplus rifle to sporting configuration after the receives were scrubbed.
Yeah, I always surface ground the front rings to ensure they were lever (front to rear) and to establish a known radius for a scope base to fit nicely. And, to clean up any arsenal attempts to deface or remove crests.
