If you are striking the mainspring, this can be dealt with as described above. If you are acually hitting the edge of the lock plate, you are in big trouble. You will have a lot of space to fill somehow when you shape your lock molding. It can be done, but would require much thought as to the best way to pull it off. If such is the case, start thinking dark stain. Really dark stain. I would suggest cutting away a sizable section of your stock from the mold area, and fitting another piece of similar wood into it, and go from there after you have re-routed the rod channel. Then dark stain.