The above house would be in Austrian possession.
For example, in order to return Mikhalkovo, it will be necessary to enter into a conflict with Austria, and in order to return Sunny, it will be necessary to conflict with the United States.
Interestingly this house already serves the community, as it appears as "House of culture"!
Obviously Austrian JW organisation already made a deal with the Moscow Towngovernment for a fair use of the house. And I think that this was already the case from the beginning.
It seems as Austria avoided such a conflict from the start and remains the owner but offered it free of cost as "house of culture" for other usage too. This is only my thoughts. However this could be a way and example for all JW posessions, kingdom halls ...become houses of culture,
And as JW are honouring all cultures anyway it is should be no problem for them to use some of the donated money for the creation of such "houses of culture" in whole Russia. What a witness if JW would support such a use of their money and property, be cooperative and so be able to stop persecution for JW. This would be a job for Austrian GB-member Gerrit Loesch, should he not visit pro-actively Moscow for checking the situation on the ground if this property serves really as house of culture and speak about future projects. Without diplomacy it will not come off to make progress.
Building a network with Moscow Towngovernment is certainly better than waiting for the attorneys and human right lawyers.

