I’m not sure what the discoloration is, but i have seen it on other Model 94 during polishing. Winchester used a few different bluing processes during the 60s and into the 80s as they tried different casting and metals in the Model 94. As a result, you won’t get a good color using standard bluing solutions. Dulite offers a solution that they state will work. I got poor results with it and had to strip is and polish it again. My recommendation is ceracoat as an alternative. All the other parts will blue nicely.