In all probability this is some form of after market damage to the stock. My reasoning for this is I have seen many stocker repairs that cover faults in a stock blank that are so good as to be virtually undetectable. The reason a stocker can cover up flaws so well is simple he has a goodly amount of spare timber that he has removed in the shaping of the stock, therefore he can choose grain type and exact figuring and colour to blend in with the finished stock to make a virtually undetectable splice or fill in. In the normal run of events of a stock damage original wood in enough quantity to choose from has a tendency to make all fill in types of repair extremely noticeable, the repair in the photograph looks like a filler of some sort has been used IMHO.
