Here is the cel and pencil drawing of Chad taking aim.
Grandpa is actually made of three cels. His head, torso, and chair are all seperate drawings.
The pencil sketch of his hover chair is pictured below.
Lou Scheimer, who was the head of Filmation thought it was important to teach children about right an wrong with his cartoons. Many of his shows like He-Man and Brave Starr included lessons at the end of the episode. There is a gallery at the Toonseum named after Pittsburgh native Lou Scheimer and if they ever do an exhibit focusing on Lou's desire to make the world a better place through cartoons I hope they display these two cels.