Joanna
The Private Dacha is the palace of emperor Alexander II. But it is not the Farm Palace. You can`t see it on Amy's map because there is big distance between this palace and the Alexandria park(some km from the right side of Amy's map). During WWII the palace was destroyed, but in 1950s-1960s was reconstructed (with new interiors) and used as a rest house.
There are only two small books about the Private Dacha:
1. Bolsheva K. Peterhof. The palace-museum "The Private Dacha".- M.-L., 1931.
2. Gushchin V.A. The Private Dacha.- SPb., 1997.
There are also some papers.
You can see the Private Dacha and the park here (first 9 pics):
http://www.enlight.ru/camera/114/index.htmlVladimir, St. Petersburg.