I have some Gerber Knives I bought in the 80's. I have 3 Blackie Collins Frisco Shivs drop points with different handle styles,and 1 double edge. I also have a Guardian 1 and a Mark 1 dagger. All are in excellent condition. Does anyone know what these are worth ? I also have a 13 inch Al-Mar Shadow dagger.Does anyone know the value of this one?