Please see this photograph at the Tulsa roundhouse of H-10-44 286.
This unit was acquired second hand from the dealer Precision National Company (PNC). Originally the locomotive was owned by the Denver and Rio Grand Western Railroad as their unit D&RGW 122. Note the red reflectors along the frame side sill. These are a characteristic feature of D&RGW units of the period. The Rio Grand retired the unit 1/19/1969.
Originally the Frisco intended to use the unit as a parts source to keep other its original units operating. However, after close inspection and determining the unit was in very good mechanical condition a decision was made to instead place the unit into active service. Also note the warning lettering above the radiator shutters "Danger Automatic Shutters Keep Clear".
Hope this helps.