Carl Panzram Killer A Journal Of Murder Thomas E Gaddis and James O Long 1970

RARE First Edition of Carl Panzram’s Killer A Journal Of Murder Thomas E. Gaddis and James O. Long 1970. The book itself is in beautiful condition minus some mildew on the very back cover, some of the back edge and backside of dustcover on back from I am assuming moisture between the dust jacket and back cover. I managed to stop it as soon as I received the book so it has not spread nor further damaged the book. But I have no idea how to properly clean it and I am terrified to damage this very rare book. So, I am leaving as is for the next owner. No writing, bent pages or damage to note otherwise.