Guerrero is a video creator who uses public domain footage to make popular “premakes” of films such as Up! (1965), The Avengers (1952), and The Empire Strikes Back (1950). His inspiring work shows a whole world of possibilities for book trailers.
If you are looking for public domain material to use in your own book trailers, you should explore the Prelinger Archives online–a collection of 60,000 “advertising, educational, industrial, and amateur” films assembled by Rick Prelinger over the last twenty years.
Here’s more about the license for the material in the archive: “Rick Prelinger and The Internet Archive hereby offer these public domain films from Prelinger Archives to all for free downloading and reuse. You are warmly encouraged to download, use and reproduce these films in whole or in part, in any medium or market throughout the world. You are also warmly encouraged to share, exchange, redistribute, transfer and copy these films, and especially encouraged to do so for free. Any derivative works that you produce using these films are yours to perform, publish, reproduce, sell, or distribute in any way you wish without any limitations.”