'bote' - The original finish on U.S. Krag receivers was Case-Hardened. (There was more to it than simply 'oil quenching' - complicated heating in ovens packed in bone or leather).

Barrels were 'browned' (blued) and this was done before assembly to case-hardened receiver.

U.S. Arsenal Refinishing instructions used at Manila Ordnance Depot in 1907 indicate: receivers were lightly polished, barrels were brushed (to remove surface rust), the bore was protected with cosmoline and sealed with wood plugs (at both ends).

The barreled-receiver was subjected to processes of: boiling lime water, caustic soda solution, browning (bluing) solution, steam chest, and carding.

There will be a difference between the finish on U.S. Krags that are 'original' armory finish and Krags that were reconditioned.

The surface colors of case-hardening do seem fragile and easily worn.

A homogeneous color on receiver and barrel suggest refinish to me.

Probably the bigger issue is who did the refinish? Armory or Aftermarket.