At approx 41:00, Ollie's black gown goes from being open and undone, (where we see her undergarments) to suddenly closed and fastened tightly.
The Baron announces Susie's salary in kronen. However, Austria's currency was changed to shillings in 1925.
The Baron's airplane has a registration number on the tail of NC394E. The "NC" indicates it is registered in the United States, not Austria, which would have begun with the two letter code "OE" at the time.