United Film Distribution Company Horror maestro Stephen King is well-known for making cameos in various movies and TV shows that were based on his novels and short stories, but there were a few instances where he appeared in projects that didn't draw on his work whatsoever. In fact, one of his best roles by far is playing the creepy Harley veteran and "cleaner" named Bachman, in the third season of Kurt Sutter's "Sons of Anarchy," who's contacted to come and dispose of a dead body. But King's first-ever cameo happened decades before the FX series, in the late George A. Romero's (who's also responsible for one of the essential zombie movies that every fan should watch at least once ) underseen 1981 action drama, "Knightriders." "Knightriders" follows a modern-day troupe re-enacting medieval customs, using altered motorcycles instead of horses to joust, and living by the proverbial sword in the '80s of Pennsylvania.…