When I first got my A1200,it had some of its keys slightly yellowed,especially letter F,and I too thought about cleaning it up.But you must remember that the Amiga yellowing is just a sign of ageing and I'd rather have a slightly yellowed Amiga that works fine,than an Amiga with a melted keyboard due to using some harsh cleaning substance being used on it.
Nothing stays new forever,so just enjoy the Amiga as it is. :-D
