More on the cunningham. They were invented to allow racing boats to pull the luff of the sail tighter without having to pull the boom down below the "low" mark on the mast. Having the boom below that mark is against the racing rules because it means your sail is bigger than the one-design class allows. You or a sailmaker could have a cunningham added to your sail, but unless you're racing, (and perhaps even if you are) a Morgan 22 probably won't need one. The downhaul on the boom probably works well enough, and a cunningham would add needless complication.