I thought you may have used lye on the stock. As an alternative to oven cleaner, you can use "Red Devil" lye powder in water. With that method, you can control the concentration and color better. The Bess guard is a good idea. The British had thousands of Brown Bess muskets over here before the Revolution. Many that were otherwise unusable were stripped for parts. If it were my pick, I'd go with the Long Land Pattern 1730 guard. It's nicer looking.