It sounds like it is just a tiny bit of cosmetic rust. I wouldn't really worry about it that much and I certainly wouldn't rub the bluing off with steel wool or anything else and make it look worse. If the remedies these gentlemen give- work without damaging the bluing, then I might try it. Otherwise I wouldn't worry about it. It won't make the gun shoot any differently. And welcome to the board. It is nice to hear from you.