Your Schrade is made with 1095 carbon steel. It contains no chromium, which is the added element that makes stainless steel stainless (at amounts of 10-13% or more, depending on the source you ask). As such, it'll oxidize very easily if unprotected. Oxidization could be black "peppering", red rust, or it could be a patina (like an old penny, door knob, or the Statue of Liberty).
A metal polish like Flitz or Simichrome can maybe remove the stains on your knife, but depending on the type and degree of oxidization, the blade may never be 100% perfect again. It could come off entirely, it could leave a "shadow", or it could leave pitting. Regardless, collector value will be damaged like any other collectable that is no longer "mint".