In my opinion something has caused the finish where the stock meets the action to wear. A number of things could have caused this (handling, someone polishing the action with the stock in place, oil softening the existing finish,etc). It is dificult to determine if the finish is original based on your photos alone. If it is not the original finish, it may just be a less than ideal refinish. If the finish is original, I would leave it alone and remove any excess oil. If not then this area can be touched up by adding more finish to the area. This is especially easy to do if the stock is finished with shellac (Parker's oringinal finish). If it is another type of finish it can be a little more difficult to have the areas of new and old finish blend evenly and may require a new top coat to the entire stock. I hope this is helpful.
