Everyone thinks of Sid Caesar, Carl Reiner and Howie Morris as appearing on Your Show of Shows in the fifties — and they did. But after that, they were on Caesar's Hour for a few years. Caesar's Hour was an hour, whereas Your Show of Shows was ninety minutes. It had fewer musical numbers and guest acts and instead of Imogene Coca as the female co-star, it had Nanette Fabray. Here's a sketch from the May 2, 1956 episode of Caesar's Hour…