You erroneously state that the 42, '43 and '44 productions were flops--actually, they were all the same Cheryl Crawford production--and ask "Success by Mandelbaum's loose standards, who knows if it made it's money back?"
You are simply wrong. Cheryl Crawford's 1942 production received rave reviews and went from Broadway to a very successful tour, so successful that it came back to Broadway for limited runs in '43 and '44. (The 1944 New York run was at City Center.) She was a shrewd producer who knew how to make money taking artistic risks and she made that production run for THREE years...DURING A WAR!
This Life Magazine from February 1942 attests to the production being a hit due to Chery Crawford's "canniness":
As for the 1952, Robert Breen production, that lasted for over FOUR years and toured internationally under the aegis of the State Department, bringing worldwide acclaim to the opera and the cast, which included William Warfield, Leontyne Price and Cab Calloway as Sportin' Life. It played Vienna, Berlin and London, then went to Latin America and the Middle East.
In 1955, it even played La Scala in Milan. The poet Maya Angelou, then starting out as an actress, played Ruby and later wrote this about the La Scala premiere:
This was something unique: famous white American performers had appeared at La Scala, but never blacks, especially not a huge cast of blacks such as Porgy provided. Both audience and company were tense. Every member of the cast was coiled tight like a spring, wound taut for a shattering release. The moment the curtain opened, the singers pulled the elegant first-night audience into the harshness of black Southern life. The love story unfolded with such tenderness that the singers wept visible tears. Time and again, the audience came to their feet, yelling and applauding. We had performed Porgy and Bess as never before, and if the La Scala patrons loved us, it was only fitting because we certainly performed as if we were in love with one another. After that. the tour went on to Moscow, and if you want to read more about that, you can pick up Truman Capote's "The Muses Are Heard." He accompanied the cast to Moscow and wrote about it for The New Yorker.
But "flop" is just not true.