Actually, I don't think JN is supposed to be elderly in this, only middle-aged. Eden was Churchill's successor, waiting for the older man to retire so he could have his turn at the helm. He would have been fifty in 1947, when Elizabeth married Phillip.
http://en.wikipedia.org/wiki/Anthony_Eden

Also, I notice Eden was known for being well dressed and even had a particular type of hat named after him--a black felt homburg.
http://en.wikipedia.org/wiki/Anthony_Eden_hat

This sounds very promising to me. You know how I love Jeremy in a hat!