I thought this was going to turn into something like Death on the Nile or Death on the Orient Express, but it took a different turn.
I am afraid my knowledge of 1930's black and white film actors is not extensive. So far I have cast:
Mr Graham, engineer protagonist, David Niven
Dr Haller, elderly German historian, ?
Banat, Romanian hit man, ?
Josette, nightclub dance, Marlene Dietrich
Jose, her boorish husband, ?
Kurtvetli, Turkish businessman, Peter Lorre,
M. Mathis, French passenger, ?
Mme. Mathis, his wife, ?
Signora Baronelli, Italian widow, ?
Signor Baronelli, her son, ?
Purser, ?
Steward, ?
Col Haki, Turkish head of secret police, ?
Kopeikin, Turkish agent, Orson Wells
Maria, nightclub hostess, ?
I can cast Orson Wells, but I don't think I can cast American actors such as Humphry Bogart. Marlene Dietrich is almost too glamorous.