In the early 1960s, movie producers adapting Ian Fleming’s novels about a suave British spy named James Bond plucked a relative unknown, Sean Connery, from obscurity and offered him the role of a lifetime. When Connery left the franchise after five movies (although he would briefly be back, in 1971, in Diamonds Are Forever) the hunt for another Bond was on.

In 1967 LIFE sent photographer Loomis Dean to casting sessions for the James Bond movie, On Her Majesty’s Secret Service. The magazine published a handful of those photos in an article on the film and on the Bond phenomenon. But some of Dean’s choicest frames — Bond wannabes suiting up, brandishing guns, sipping faux martinis, wooing women — never ran in the magazine.

Here, LIFE.com presents photos from those 1967 auditions, featuring the five top candidates — including George Lazenby, who would eventually win the coveted role.

[Buy the LIFE book, 50 Years of James Bond.]

Critical reception of On Her Majesty’s Secret Service has hardly been uniform. There was much initial grumbling, for example, about Lazenby’s performance — especially in light of Connery effectively defining the role for a generation of moviegoers. Lazenby was a 28-year-old Australian model living in London, with virtually no acting experience outside TV commercials. But there was something about George Lazenby that placed him a notch above his competitors. Particularly impressive was his physical prowess. (In a subsequent audition to test his fighting skills, Lazenby reportedly broke a stuntman’s nose. That clinched it.)

“I’m really looking forward to being Bond, for the bread and the birds,” he told LIFE after his casting.

Meanwhile, the years have been kind to the 1969 flick. Entertainment Weekly, for example, ranked On Her Majesty’s Secret Service the sixth best of the Bond series, which now includes more than 20 feature films and is one of the highest-grossing movie franchises of all time.