According to the Vintage Male Physique blog, Richard Bennett was photographed in both nude and semi-nude poses, primarily by Danny Fitzgerald. Not much is known about Danny Fitzgerald, except that he published under the name Demi-Dieux, Demi-Gods, in magazines like Demi Gods and Young Physique during the 1960s.
And intensely homoerotic. No way could you buy these magazines under the pretense that you were looking for musclebuilding tips.
Richard Bennett was not a pro bodybuilder, but he does appear on the rosters of amateur competitions from the late 1940s through 1965. He had no wins, but he could have.
A correspondent stated that he still lives in New York City and he has a house upstate, so he must be an economic success. And he has a brother who looks like James Dean.
That's all. Otherwise, even in the Age of the Internet, Richard Bennett remains a mystery.