If you are referring to S marked Mk. I sights with the micrometer elevation adjustment, only early Savages would have had these originally fitted. Because No. 4 sights are essentially interchangeable, any pattern of sight can turn up on any No. 4 regardless of what was on the rifle originally. I suspect that the majority of Savage rifles would have left Chicopee Falls with Mk. II 300/600 sights. While still in service, they would have been subject to whatever sight upgrades were authorized.