Regarding the "camera trickery" in the finale number of "Ziegfeld Girl" that Capt D McMars mentions, I presume this refers to the substitution of Judy Garland for Virginia Bruce at the top of the huge revolving staircase set they built for "The Great Ziegfeld" in 1946, the footage of which was...
The quality of this isn't up to the standard of the French DVD. I have both and far prefer the French release.
https://www.fnac.com/a1937776/Le-Chant-du-Danube-Esmond-Knight-DVD-Zone-2
Alistair