Apparently I'm a bad flint owner. Haven't shot for a while and had a look at it today and saw it. It's on the face of the frizzen, A little on the hammer, and some dots on the barrel.I thought I cleaned it up well but obviously not.I didn't think there was anything you put on the frizzen to prevent this, am I wrong? I don't think I touched the frizzen to get oil on it from my finger,I ran a cloth across it to clean it, I guess I must have touched it and not known it. Your recommendations are greatly appreciated.