The gassing footage was not shown before 1948. The original (if this collated sequence of scenes isn't the original) is lost.
Most of the biographical material on Goldschmidt comes from the book Kultur auf Trümmern: Berliner Berichte der amerikanischen Information Control Section Juli-Dezember 1945 by Brewster Chamberlin, originally published in 1979. It is mostly a compilation of OMGUS and other reports on the film, theater, and music industries in Germany immediately after the war.
Goldschmidt was a representative of Metro-Goldwyn-Mayer in Germany before 1933. It's also claimed he was a distant relative of the Goldschmidt-Rothschild family. A half-Jew, he went into hiding in Berlin during the war.
The American military government appointed him head of film distribution in July 1945.
In 1945, the Americans were negotiating with with Soviet film distributor Sojusintorgkino to bring English-language films to Soviet-controlled theaters. The Soviets also supplied films to be shown in the American sector. One report states Goldschmidt retained excellent relations with the British and Soviet film distribution representatives.
So it's more likely that the Soviets filmed the purported gassing scenes, handed the film reel to Goldschmidt, and in 1947 he handed it to Schulberg who put it into Nuremberg: Its Lesson for Today.
And the film is likely a staged re-imagining of Akimova Natalia Nikolaevna's testimony in "Trial in the case of atrocities committed by the German fascist invaders in the Belarusian SSR" (Судебный процесс по делу о злодеяниях, совершенных немецко-фашистскими захватчиками в Белорусской ССР (15-29 января 1946 года) [link].
Testimony of Natalia Nikolaevna Akimova here.
That's the detailed information on the gassing procedure, which doesn't exactly match the film. She testifies there were two gassings: 20 people gassed on September 17, 1941, then 180 more (200 total) on November 4.I went with Doctor Kitayevich to the bathhouse, near which trucks and cars were parked. A German, who called himself a chemist, was fiddling around near the cars. A hose went from the car to the bathhouse doors. Another pipe went from the bathhouse window to the generator of another car. The bathhouse was hermetically sealed, and there were several sick people in it.
Half an hour later, the Germans opened the bathhouse doors and began throwing corpses into the cars. The cars with corpses left the colony territory.
Interestingly, she identifies herself as a doctor in the Minsk Psychiatric Hospital in Novinki, which is the WRONG LOCATION THAT I SPENT HALF A DAY TRACKING DOWN before Wetzelrad found the correct location of the film. So the film was shot at the wrong psychiatric hospital, or she testified she was at the wrong hospital.
