Well, here's good news, a letter to the editor of the New York Times written by Harrison Cannold in November 1965. This is our first sighting of Harrison after WWII, and it opens up likely avenues for learning more about his life and possible descendents. It is even remotely possible that he is still living. I don't have his birth date handy, but will look for it on the 1920 or 1930 census record that we have.
That Harrison was interested in the political situation in Rhodesia, now Zimbabwe, is not surprising for a member of our politically attuned family. Here is the clipping: