Of course it is. The rightful owners of property/land are those that hold the title deeds.
So it makes no difference to you whether it is sat as it ever was, whether any buildings on it have been demolished or are being occupied, whether anything growing there has gone or whether 2 thousand new homes sit on it now?
Your hope is what? Just to get it back? Or to be able to live in or on it? How do you hope to achieve that if you don't know what the status of it now is?
Your president is bargaining about all this. He is not asking for every square inch of GC land to be returned to its rightful owner is he? Or do you imagine he is?
Can anyone confirm what I've heard that there was actually a short period of time when the GC side DID agree to this 'exchange' idea? But that they had to go back on that on account of it being so unpopular? I've heard that they did, at first, agree but later withdrew that agreement.