They correspond to the Ten Commandments. He steals nerve gas from the U.S. Army and leaves a tablet with the number 8 chisled in it. (Thou Shall Not Steal.) He has enslaved his parents at a rock quarry in Greece and has painted the number 5 all over the place. (Thou Shall Honor Thy Mother and Father)
Yes, they're shown in this episode. That footage was removed from the theatrical movie version of the story, "One Spy Too Many."
