The mural is by Chuck Arnett, "best known for the most celebrated element of the Tool Box bar in San Francisco, a huge mural painted by Chuck, a local artist who worked at the bar and whose paintings and posters were also featured at such later bars as the Red Star Saloon and the Ambush. The mural was a massive black-and-white painting that depicted a variety of tough-looking, masculine men." (via the leather archives)
The Tool Box opened in 1961 and closed in 1971. Life Magazine's photographer was referred to The Tool Box by Hal Call, leader of the San Francisco chapter of the Mattachine Society, who had long worked to dispel the myth that all homosexual men were effeminate.