Christmas gift for teen

My nephew is 16 years old and has been working with a welder/metalsmith to make swords. I do not live near him and I haven’t had a chance to talk to him much about this yet. I do know this is a very important creative outlet for him. It’s completely his thing. To my question, is there a book, tool, resource that anyone could recommend as Christmas gift for him? I was ideally thinking of a book. Perhaps a historical one? I’m asking here, cause I do not want anything obvious/popular. I need insight from someone who knows this shit and a cool recommendation. Thanks in advance.