It's always a challenge to keep older cats interested in eating. When a cat refuses everything, I usually turn to baby food - the pureed lamb, veal, or chicken - it can "spoil" a cat into wanting only baby food from then on, but sometimes it's the only way to keep them eating!
Also, there's a pour on gravy (
http://www.amazon.com/s/ref=nb_sb_no...%3Daps&x=0&y=0) that can get a finicky cat interested in eating again.