The Internet Broadway Database says Hingle took over the role on 28 February 1966 and apparently finished out the run, which lasted until July of 1967. (Here’s a NY Times clipping from June 1966 mentioning Hingle and Eddie Bracken, who had replaced original star Art Carney as Felix Ungar.)
Matthau, of course, then played Oscar in the hit 1968 film The Odd Couple. And Klugman played Oscar (opposite Tony Randall) on the TV series from 1970-75. If they had just done an Odd Couple video game in the 1980s, Hingle would have been a shoo-in.
Hingle was a Hollywood nearly-man of sorts. Most notably, he was cast in the title role of the film Elmer Gantry in 1958, but lost the role after he fell 58 feet down an elevator shaft and was critically injured. (And lost a finger.) Burt Lancaster took over the role and won an Oscar as best actor.
But Hingle didn’t seem to mind too much. As he reportedly told the NY Times, “I’ve had exactly the kind of career I hoped for.”
As an aside, The Times has posted its giddy original review of The Odd Couple, with Matthau, from 10 March 1965.
The Odd Couple has it made. Women are bound to adore the sight of a man carrying on like a little homemaker. Men are sure to snicker at a male in domestic bondage to a man. Kids will love it because it’s funny. Homosexuals will enjoy it — for obvious reasons. Doesn’t that take care of everyone?