How Much Was True?

I thought the film was based on an intriguing, if somewhat fanciful story, but I wonder how much of it was true.

I know that the movie is based on Thomas Rosenboom's book PUBLIC WORKS (so far, it hasn't been translated into English), and I know that the real hotel was actually built around these two apartments. You can google a picture of the Park Plaza Victoria Amsterdam Hotel and you can clearly see that they are still there today, and according to the hotel's website they are presently souvenir shops.

The owners of the two apartments really did hold out for more money, but the whole story about the Jewish village leaving the country and their voyage being paid for by a valuable violin might or might not be true.

I'd like to know if anyone knows if that part of the story is actually based on fact. Although the film works either way.

Free to those that can afford it, very expensive to those that can