I've looking for this movie: (I think its a famous classical movie but when I Google it, the words are so common that I can't find anything relevant)
The movie is about a robbery in a train, for a security box. The thieves use some kind of wax or soup to duplicate the keys. The train is a an old train (but I don't know if its electrical or steam), oriented in the end of the 19th century (1890s maybe).
I just remember a few scenes. I remember a white-haired wise old man as Master-chief of the robbery plan or something like that.