The dolls house created by Petronella Oortman between ca. 1686-1710 is part of the collection of the Rijksmuseum at Amsterdam, and can be seen in room 2.20. However, the original is very different from the one presented in the TV-series, and all dolls except one are missing.
The actual dollshouse owned by Petronella Oorthuis can be seen at the Rijksmuseum in Amsterdam.
Canal houses in Amsterdam always have steps leading up to the front door. They usually have steps leading down to a basement/cellar as well, but the ground floor of the houses are never on the same level as the canal -as this one was depicted. Major mistake. Also the steps up to the front door are often mentioned in the novel, as they are a feature of the house.