Knave is published under a Creative Commons license, so you are free to do anything you want with the text, including translating and selling it, as long as you give attribution to me.
My name is Rogério and I have a small publisher in Brazil, and we publish independent RPGs in Portuguese. And I would like to know if we could make a translation for Brazil. :)
Here is my email: editorialhuginnemuninn@gmail.com