There are some short YouTube clips about Magnum here and here. You can find some biographical information about him here.
For more images of vintage men and their relationships (some gay, some straight) visit: Two Men and Their Dog; Adam and Steve in the Garden of Eden: On Intimacy Between Men; A Man and His Dog; The Beasts of West Point; Vintage Men: Innocence Lost | The Photography of William Gedney; It's Only a Paper Moon;Vintage Gay America: Crawford Barton; These Men Are Not Gay | This Is Not A Farmer | Disfarmer; Desire and Difference: Hidden in Plain Sight, Come Make Eyes With Me Under the Anheuser Bush, Hugh Mangum: Itinerant Photographer, Two men, Two Poses; Photos are Not Always What They Seem,Vintage Sailors: An Awkward Realization, Three Men on a Horse, Welkom Bar: Vintage Same Sex Marriage, Pretty in Pink: Two Vintage Chinese Men, Memorial Day Surprise: Vintage Sailor Love, Memorial Day: Vintage Dancing Sailors, The Curious Case of Two Men Embracing, They'll Never Know How Close We Were, Vintage Love: Roger Miller Pegram,Manly Affections: Robert Gant, Homo Bride and Groom Restored to Dignity, The Men in the Trees, The Girl in the Outhouse, Tommy and Buzz: All My Love,Men in Photo Booths, and Invisible: Philadelphia Gay Wedding c. 1957. You can also follow me on Tumblr.
After the page break I've included some of the most striking examples of his work that depict friendship between men. I'll upload a larger cross section of his work to my Tumblr page and put the links here.