I'd also be grateful for any information, or pointings in the direction thereof, of (to quote a friend who knows something about this period but not enough for my purposes) 'whether films were shot with direct or post-synchronised sound, or of how advanced the German industry was in this regard. Hollywood films of the period c. 1928 - 33 are notorious for stagey, static mise en scene because of the need to consider where the microphones were, whereas Italian films of the same period, which were always post-synchronised, maintained silent era camera fluidity.'
[He's doing a PhD in film so is allowed to use phrases like 'mise-en-scene'. :)]
It's for reasons like this that I'm a bit worried about simply picking up a biography of a Hollywood star of that period and trying to use the information there!
I know this is pretty obscure, but many thanks.