The link below will take you to a film documenting the life and times of Forrest J Ackerman. It is called FAMOUS MONSTER FORREST J ACKERMAN, and was made near the end of Forry's life. A number of Forry's friends are interviewed in the film including Ray Harryhausen, George Clayton Johnson and, yes, Ray Bradbury!

https://www.youtube.com/watch?v=IXUZKcZqth8