World War I gave the Brits a lot of seriously handicapped shooters. They tried to carry on their previous life-style, of which shooting had been a very important social event (remember, very limited entertainment by today's standards - no TV, little radio, no movies to speak of, etc.). If one was going to shoot, then one needed to shoot well. Try one hand shooting with a regular gun and see how long before you start thinking about some helpful modifictions. I occasionally assist a stroke victim who can use only one arm - this would probably be a real boon for him.