great to hear of your success. i introduced felix to S when S was about 5. it took some adjustments but they have worked out their problems and i think they are even friends now. S was introduced to halley when hal was about 10; they too lived together well and were both the happier for it. the most helpful advice i've read is to introduce them slowly, at their own pace. amazing cats' ability to coexist with other cats when they have no say in the matter.