Joe Gibson is an English actor and stand-in who worked as a wet suit stuntman, Snowtrooper and Stormtrooper in ESB. In RotJ, he was a stand-in for Mark Hamill as well as a Gamorrean Guard and Stormtrooper. I also just discovered a signed photo of him supposedly standing in as RotJ Boba Fett for the photos against the green screen... I am looking to get further confirmation from the seller of the photo. Please let me know if you know anything. Thanks!