Charles I have no doubt that you are very experienced. But emulsion scratches can be fixed with an Adams machine. I've been using one for a little while myself. There is more than one way to accomplish this and I agree, it will take some practice to become efficient with an Adams machine.You can use graphite on both sides of the negative. Using retouching fluid will give you the tooth needed for the graphite to adhere. If the scratch is a radical one you can use dye on the base side to cover most of the scratch then blend with graphite on the emulsion side. If you have pinholes then this can be fixed with the abrading tool. An etching knife is used for removing emulsion to allow more light to pass through. All of these techniques and tools require a touch that can only be achieved with practice. I use mine on 8x10 and 8x20 negatives so I don't have much experience on the smaller formats but the principles and techniques are the same. A good starting point would be Veronica Cass Weiss' book "Retouching From Start to Finish". A good example of what can be done with graphite retouching is a lot of Hurrell's Hollywood portraits. He was a master at it.